Heratio Help Center article. Category: Plugin Reference.

ahgPreservationPlugin - Technical Documentation

Overview

The ahgPreservationPlugin provides comprehensive digital preservation capabilities for Heratio, implementing OAIS (Open Archival Information System) and PREMIS (Preservation Metadata Implementation Strategies) standards. The plugin includes PRONOM-based format identification (using Siegfried), virus scanning, format conversion, backup verification, and replication features.

Version: 1.5.0 Category: Preservation Dependencies: atom >= 2.8.0, PHP >= 8.1

Optional Dependencies:

Siegfried (PRONOM format identification)
ClamAV (virus scanning)
ImageMagick (image conversion)
FFmpeg (audio/video conversion)
LibreOffice (document conversion)
Ghostscript (PDF processing)

Architecture

Component Diagram

+-------------------------------------------------------------------------+
|                        ahgPreservationPlugin                             |
+-------------------------------------------------------------------------+
|                                                                          |
|  +-------------------------------------------------------------------+  |
|  |                      PRESENTATION LAYER                            |  |
|  +-------------------------------------------------------------------+  |
|  |  +----------+ +----------+ +----------+ +----------+ +----------+ |  |
|  |  |Dashboard | |Identific | |VirusScan | |Conversion| | Backup   | |  |
|  |  | Template | | Template | | Template | | Template | | Template | |  |
|  |  +----------+ +----------+ +----------+ +----------+ +----------+ |  |
|  +-------------------------------------------------------------------+  |
|                                    |                                     |
|                                    v                                     |
|  +-------------------------------------------------------------------+  |
|  |                      CONTROLLER LAYER                              |  |
|  +-------------------------------------------------------------------+  |
|  |                    actions.class.php                               |  |
|  |  +------------+ +------------+ +------------+ +------------+       |  |
|  |  |executeIndex| |executeVirus| |executeConv | |executeBackup|      |  |
|  |  +------------+ +------------+ +------------+ +------------+       |  |
|  +-------------------------------------------------------------------+  |
|                                    |                                     |
|                                    v                                     |
|  +-------------------------------------------------------------------+  |
|  |                       SERVICE LAYER                                |  |
|  +-------------------------------------------------------------------+  |
|  |                   PreservationService.php                          |  |
|  |  +---------------------------------------------------------------+ |  |
|  |  | Checksum Operations    | Fixity Verification    |             | |  |
|  |  | generateChecksums()    | verifyFixity()         |             | |  |
|  |  | getChecksums()         | runBatchFixityCheck()  |             | |  |
|  |  +---------------------------------------------------------------+ |  |
|  |  | Format Identification  | Virus Scanning         |             | |  |
|  |  | identifyFormat()       | scanForVirus()         |             | |  |
|  |  | runBatchIdentification | runBatchVirusScan()    |             | |  |
|  |  | isSiegfriedAvailable() | isClamAvAvailable()    |             | |  |
|  |  +---------------------------------------------------------------+ |  |
|  |  | Format Conversion      | Backup & Replication   |             | |  |
|  |  | convertFormat()        | verifyBackup()         |             | |  |
|  |  | getConversionTools()   | verifyAllBackups()     |             | |  |
|  |  | selectConversionTool() | getStatistics()        |             | |  |
|  |  +---------------------------------------------------------------+ |  |
|  +-------------------------------------------------------------------+  |
|                                    |                                     |
|                                    v                                     |
|  +-------------------------------------------------------------------+  |
|  |                         CLI TASKS                                  |  |
|  +-------------------------------------------------------------------+  |
|  | preservationIdentifyTask    | preservationFixityTask              |  |
|  | preservationVirusScanTask   | preservationConvertTask             |  |
|  | preservationVerifyBackupTask| preservationReplicateTask           |  |
|  +-------------------------------------------------------------------+  |
|                                    |                                     |
|                                    v                                     |
|  +-------------------------------------------------------------------+  |
|  |                       DATA LAYER                                   |  |
|  +-------------------------------------------------------------------+  |
|  |         Illuminate\Database\Capsule\Manager (Laravel QB)          |  |
|  +-------------------------------------------------------------------+  |
|                                                                          |
+-------------------------------------------------------------------------+

Database Schema

Entity Relationship Diagram

+-------------------------------------------------------------------------+
|                    PRESERVATION DATABASE SCHEMA                          |
+-------------------------------------------------------------------------+

+----------------------+          +----------------------+
|    digital_object    |          |  information_object  |
|   (Heratio Core Table)  |          |   (Heratio Core Table)  |
+----------------------+          +----------------------+
| PK id                |          | PK id                |
|    name              |          |    ...               |
|    path              |          +----------------------+
|    byte_size         |                    ^
|    object_id --------+--------------------|
+----------------------+
         |
         | 1:N
         v
+----------------------+     +----------------------+
| preservation_checksum|     |preservation_fixity_  |
+----------------------+     |       check          |
| PK id                |     +----------------------+
| FK digital_object_id |<----| PK id                |
|    algorithm         |     | FK digital_object_id |
|    checksum_value    |     | FK checksum_id       |
|    file_size         |     |    algorithm         |
|    generated_at      |     |    expected_value    |
|    verified_at       |     |    actual_value      |
|    verification_     |     |    status            |
|      status          |     |    error_message     |
|    created_at        |     |    checked_at        |
|    updated_at        |     |    checked_by        |
+----------------------+     |    duration_ms       |
                             |    created_at        |
                             +----------------------+

+----------------------+     +----------------------+
| preservation_virus_  |     |preservation_format_  |
|        scan          |     |     conversion       |
+----------------------+     +----------------------+
| PK id                |     | PK id                |
| FK digital_object_id |     | FK digital_object_id |
|    scan_engine       |     |    source_format     |
|    engine_version    |     |    source_mime_type  |
|    signature_version |     |    target_format     |
|    status            |     |    target_mime_type  |
|    threat_name       |     |    conversion_tool   |
|    file_path         |     |    tool_version      |
|    file_size         |     |    status            |
|    scanned_at        |     |    source_path       |
|    scanned_by        |     |    source_size       |
|    duration_ms       |     |    source_checksum   |
|    error_message     |     |    output_path       |
|    quarantined       |     |    output_size       |
|    quarantine_path   |     |    output_checksum   |
|    created_at        |     |    conversion_options|
+----------------------+     |    started_at        |
                             |    completed_at      |
                             |    duration_ms       |
                             |    error_message     |
                             |    created_by        |
                             |    created_at        |
                             +----------------------+

+----------------------+     +----------------------+
|preservation_backup_  |     |preservation_replica- |
|    verification      |     |    tion_target       |
+----------------------+     +----------------------+
| PK id                |     | PK id                |
|    backup_type       |     |    name              |
|    backup_path       |     |    target_type       |
|    backup_size       |     |    connection_config |
|    original_checksum |     |    description       |
|    verified_checksum |     |    is_active         |
|    status            |     |    last_sync_at      |
|    verification_     |     |    created_at        |
|      method          |     |    updated_at        |
|    files_checked     |     +----------------------+
|    files_valid       |              |
|    files_invalid     |              | 1:N
|    files_missing     |              v
|    verified_at       |     +----------------------+
|    verified_by       |     |preservation_replica- |
|    duration_ms       |     |      tion_log        |
|    error_message     |     +----------------------+
|    details (JSON)    |     | PK id                |
|    created_at        |     | FK target_id         |
+----------------------+     | FK digital_object_id |
                             |    operation         |
+----------------------+     |    file_path         |
|  preservation_event  |     |    file_size         |
+----------------------+     |    checksum          |
| PK id                |     |    status            |
| FK digital_object_id |     |    error_message     |
| FK information_      |     |    started_at        |
|      object_id       |     |    completed_at      |
|    event_type        |     |    duration_ms       |
|    event_datetime    |     |    created_at        |
|    event_detail      |     +----------------------+
|    event_outcome     |
|    event_outcome_    |
|      detail          |
|    linking_agent_    |
|      type            |
|    linking_agent_    |
|      value           |
|    created_at        |
+----------------------+

+----------------------+     +----------------------+
| preservation_format  |     |preservation_object_  |
+----------------------+     |      format          |
| PK id                |     +----------------------+
|    puid              |<----| PK id                |
|    mime_type         |     | FK digital_object_id |
|    format_name       |     | FK format_id         |
|    format_version    |     |    puid              |
|    extension         |     |    mime_type         |
|    risk_level        |     |    format_name       |
|    risk_notes        |     |    format_version    |
|    preservation_     |     |    identification_   |
|      action          |     |      tool            |
| FK migration_        |     |    identification_   |
|      target_id       |     |      date            |
|    is_preservation_  |     |    confidence        |
|      format          |     |    basis             |
|    created_at        |     |    warning           |
|    updated_at        |     |    created_at        |
+----------------------+     +----------------------+

Database Tables

preservation_virus_scan

Records virus scan results for digital objects.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`digital_object_id`	INT FK	Reference to digital_object
`scan_engine`	VARCHAR(50)	Scanner used (e.g., 'clamav')
`engine_version`	VARCHAR(50)	Scanner version
`signature_version`	VARCHAR(50)	Virus signature version
`status`	ENUM	clean, infected, error, skipped
`threat_name`	VARCHAR(255)	Name of detected threat
`file_path`	VARCHAR(1024)	Path to scanned file
`file_size`	BIGINT UNSIGNED	File size in bytes
`scanned_at`	DATETIME	When scan was performed
`scanned_by`	VARCHAR(100)	User or 'system'/'cron'
`duration_ms`	INT UNSIGNED	Scan duration in milliseconds
`error_message`	TEXT	Error details if failed
`quarantined`	TINYINT(1)	Whether file was quarantined
`quarantine_path`	VARCHAR(1024)	Path in quarantine

preservation_format_conversion

Records format conversion operations.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`digital_object_id`	INT FK	Reference to digital_object
`source_format`	VARCHAR(50)	Original file extension
`source_mime_type`	VARCHAR(100)	Original MIME type
`target_format`	VARCHAR(50)	Target file extension
`target_mime_type`	VARCHAR(100)	Target MIME type
`conversion_tool`	VARCHAR(100)	Tool used (imagemagick, ffmpeg, etc.)
`tool_version`	VARCHAR(50)	Tool version
`status`	ENUM	pending, processing, completed, failed
`source_path`	VARCHAR(1024)	Path to source file
`source_size`	BIGINT UNSIGNED	Source file size
`source_checksum`	VARCHAR(128)	Source file SHA-256
`output_path`	VARCHAR(1024)	Path to converted file
`output_size`	BIGINT UNSIGNED	Converted file size
`output_checksum`	VARCHAR(128)	Converted file SHA-256
`conversion_options`	JSON	Options used for conversion
`started_at`	DATETIME	Conversion start time
`completed_at`	DATETIME	Conversion completion time
`duration_ms`	INT UNSIGNED	Conversion duration
`error_message`	TEXT	Error details if failed
`created_by`	VARCHAR(100)	User who initiated

preservation_backup_verification

Records backup verification results.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`backup_type`	ENUM	database, files, full
`backup_path`	VARCHAR(1024)	Path to backup
`backup_size`	BIGINT UNSIGNED	Backup size in bytes
`original_checksum`	VARCHAR(128)	Expected checksum
`verified_checksum`	VARCHAR(128)	Calculated checksum
`status`	ENUM	valid, invalid, corrupted, missing, warning, error
`verification_method`	VARCHAR(50)	Method used (sha256, etc.)
`files_checked`	INT UNSIGNED	Number of files verified
`files_valid`	INT UNSIGNED	Files that passed
`files_invalid`	INT UNSIGNED	Files that failed
`files_missing`	INT UNSIGNED	Missing files
`verified_at`	DATETIME	When verification ran
`verified_by`	VARCHAR(100)	User or 'system'
`duration_ms`	INT UNSIGNED	Verification duration
`error_message`	TEXT	Error details
`details`	JSON	Additional verification details

preservation_replication_target

Defines backup replication destinations.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`name`	VARCHAR(255)	Target name
`target_type`	ENUM	local, sftp, rsync, s3
`connection_config`	JSON	Connection parameters
`description`	TEXT	Target description
`is_active`	TINYINT(1)	Whether target is enabled
`last_sync_at`	DATETIME	Last successful sync
`created_at`	DATETIME	Record creation time
`updated_at`	DATETIME	Last update time

Connection Config JSON Structure:

Local:

{
    "path": "/var/backups/atom"
}

SFTP/Rsync:

{
    "host": "backup.example.com",
    "port": 22,
    "path": "/backups/atom",
    "user": "backup"
}

S3:

{
    "bucket": "my-bucket",
    "region": "us-east-1"
}

preservation_replication_log

Records replication operations.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`target_id`	BIGINT FK	Reference to replication_target
`digital_object_id`	INT FK	Reference to digital_object (nullable)
`operation`	ENUM	upload, verify, delete
`file_path`	VARCHAR(1024)	Source file path
`file_size`	BIGINT UNSIGNED	File size
`checksum`	VARCHAR(128)	File checksum
`status`	ENUM	started, completed, failed
`error_message`	TEXT	Error details
`started_at`	DATETIME	Operation start
`completed_at`	DATETIME	Operation end
`duration_ms`	INT UNSIGNED	Operation duration

preservation_package

Main table for OAIS packages (SIP/AIP/DIP).

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`uuid`	CHAR(36) UK	Unique package identifier
`name`	VARCHAR(255)	Package name
`description`	TEXT	Package description
`package_type`	ENUM	sip, aip, dip
`status`	ENUM	draft, building, complete, validated, exported, error
`package_format`	ENUM	bagit, zip, tar, directory
`bagit_version`	VARCHAR(10)	BagIt version (default 1.0)
`object_count`	INT UNSIGNED	Number of objects in package
`total_size`	BIGINT UNSIGNED	Total package size in bytes
`manifest_algorithm`	VARCHAR(20)	Checksum algorithm (sha256)
`package_checksum`	VARCHAR(128)	Overall package checksum
`source_path`	VARCHAR(1024)	Path to built package directory
`export_path`	VARCHAR(1024)	Path to exported archive file
`originator`	VARCHAR(255)	Creating organization
`submission_agreement`	VARCHAR(255)	Reference to agreement
`retention_period`	VARCHAR(100)	Retention policy
`parent_package_id`	BIGINT FK	Parent package (for conversions)
`information_object_id`	INT FK	Linked archival description
`created_by`	VARCHAR(100)	Creator user
`created_at`	DATETIME	Creation timestamp
`built_at`	DATETIME	When package was built
`validated_at`	DATETIME	When package was validated
`exported_at`	DATETIME	When package was exported
`metadata`	JSON	Additional metadata

preservation_package_object

Links digital objects to packages.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`package_id`	BIGINT FK	Reference to preservation_package
`digital_object_id`	INT FK	Reference to digital_object
`relative_path`	VARCHAR(1024)	Path within package (e.g., data/file.pdf)
`file_name`	VARCHAR(255)	File name
`file_size`	BIGINT UNSIGNED	File size in bytes
`checksum_algorithm`	VARCHAR(20)	Checksum algorithm used
`checksum_value`	VARCHAR(128)	File checksum
`mime_type`	VARCHAR(100)	MIME type
`puid`	VARCHAR(50)	PRONOM identifier
`object_role`	ENUM	payload, metadata, manifest, tagfile
`sequence`	INT UNSIGNED	Order in package
`added_at`	DATETIME	When object was added

preservation_package_event

Records package lifecycle events.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`package_id`	BIGINT FK	Reference to preservation_package
`event_type`	ENUM	creation, modification, building, validation, export, import, transfer, deletion, error
`event_datetime`	DATETIME	When event occurred
`event_detail`	TEXT	Event description
`event_outcome`	ENUM	success, failure, warning
`event_outcome_detail`	TEXT	Additional outcome details
`agent_type`	VARCHAR(50)	Agent type (software, human)
`agent_value`	VARCHAR(255)	Agent identifier
`created_by`	VARCHAR(100)	User who triggered event

Service Layer API

PreservationService

Main service class providing all preservation operations.

Format Identification (Siegfried/PRONOM)

/**
 * Check if Siegfried is available
 *
 * @return bool
 */
public function isSiegfriedAvailable(): bool

/**
 * Get Siegfried version information
 *
 * @return array|null Version info including version and signature_date
 */
public function getSiegfriedVersion(): ?array

/**
 * Identify format using Siegfried (PRONOM)
 *
 * @param int  $digitalObjectId
 * @param bool $updateRegistry   Add format to registry if new
 * @return array Results with puid, format_name, mime_type, confidence, basis, warning
 */
public function identifyFormat(int $digitalObjectId, bool $updateRegistry = true): array

/**
 * Re-identify an already identified object
 *
 * @param int $digitalObjectId
 * @return array Results with updated identification
 */
public function reidentifyFormat(int $digitalObjectId): array

/**
 * Batch identification for multiple objects
 *
 * @param int  $limit            Maximum objects to identify
 * @param bool $unidentifiedOnly Only identify objects without existing identification
 * @param bool $updateRegistry   Add new formats to registry
 * @return array Summary with identified, failed, skipped counts
 */
public function runBatchIdentification(int $limit = 100, bool $unidentifiedOnly = true, bool $updateRegistry = true): array

/**
 * Get identification statistics
 *
 * @return array Stats including total_objects, identified, unidentified, by_confidence, top_formats
 */
public function getIdentificationStatistics(): array

/**
 * Get identification history
 *
 * @param int         $limit      Maximum records
 * @param string|null $confidence Filter by confidence level
 * @return array Identification records
 */
public function getIdentificationLog(int $limit = 100, ?string $confidence = null): array

Virus Scanning

/**
 * Check if ClamAV is available
 *
 * @return bool
 */
public function isClamAvAvailable(): bool

/**
 * Get ClamAV version information
 *
 * @return array|null Version info or null if not installed
 */
public function getClamAvVersion(): ?array

/**
 * Scan a digital object for viruses
 *
 * @param int    $digitalObjectId
 * @param bool   $quarantine      Move infected files to quarantine
 * @param string $scannedBy       User or system identifier
 * @return array Scan results with status, threat_name, quarantined, etc.
 */
public function scanForVirus(int $digitalObjectId, bool $quarantine = true, string $scannedBy = 'system'): array

/**
 * Batch virus scan for multiple objects
 *
 * @param int    $limit     Maximum objects to scan
 * @param bool   $newOnly   Only scan unscanned objects
 * @param string $scannedBy Identifier
 * @return array Summary with clean, infected, errors counts
 */
public function runBatchVirusScan(int $limit = 100, bool $newOnly = true, string $scannedBy = 'cron'): array

/**
 * Get virus scan history
 *
 * @param int         $limit  Maximum records
 * @param string|null $status Filter by status
 * @return array Scan records
 */
public function getVirusScanLog(int $limit = 100, ?string $status = null): array

Format Conversion

/**
 * Get available conversion tools
 *
 * @return array Tool information (imagemagick, ffmpeg, ghostscript, libreoffice)
 */
public function getConversionTools(): array

/**
 * Convert a digital object to a different format
 *
 * @param int    $digitalObjectId
 * @param string $targetFormat     Target format (tiff, pdf, mp4, etc.)
 * @param array  $options          Conversion options (quality, compress, etc.)
 * @param string $createdBy        User identifier
 * @return array Result with success, output_path, output_size, etc.
 */
public function convertFormat(int $digitalObjectId, string $targetFormat, array $options = [], string $createdBy = 'system'): array

/**
 * Get conversion history
 *
 * @param int         $limit  Maximum records
 * @param string|null $status Filter by status
 * @return array Conversion records
 */
public function getConversionLog(int $limit = 100, ?string $status = null): array

Backup Verification

/**
 * Verify backup integrity
 *
 * @param string      $backupPath       Path to backup file or directory
 * @param string      $backupType       Type: database, files, full
 * @param string|null $expectedChecksum Expected checksum if known
 * @param string      $verifiedBy       User identifier
 * @return array Results with status, files_checked, files_valid, etc.
 */
public function verifyBackup(string $backupPath, string $backupType = 'full', ?string $expectedChecksum = null, string $verifiedBy = 'system'): array

/**
 * Verify all backups in a directory
 *
 * @param string|null $backupDir   Backup directory (default: uploads/backups)
 * @param string      $verifiedBy  Identifier
 * @return array Summary with total, valid, invalid counts
 */
public function verifyAllBackups(string $backupDir = null, string $verifiedBy = 'cron'): array

/**
 * Get backup verification history
 *
 * @param int         $limit  Maximum records
 * @param string|null $status Filter by status
 * @return array Verification records
 */
public function getBackupVerificationLog(int $limit = 100, ?string $status = null): array

Extended Statistics

/**
 * Get extended statistics including new features
 *
 * @return array Statistics including virus_scans_30d, conversions_30d, etc.
 */
public function getExtendedStatistics(): array

CLI Tasks

preservationSchedulerTask

Runs scheduled preservation workflows based on their configured schedules.

Location: lib/task/preservationSchedulerTask.class.php

Namespace: preservation:scheduler

Options:

Option	Default	Description
`--status`	-	Show scheduler status and statistics
`--list`	-	List all configured schedules
`--run-id=N`	-	Run a specific schedule by ID
`--dry-run`	-	Show what would be run without executing

Usage:

# Run all due workflows (intended for cron)
php symfony preservation:scheduler

# Show scheduler status
php symfony preservation:scheduler --status

# List all schedules
php symfony preservation:scheduler --list

# Run specific schedule
php symfony preservation:scheduler --run-id=1

# Preview without running
php symfony preservation:scheduler --dry-run

Cron Setup:

# Run scheduler every minute
* * * * * cd /usr/share/nginx/archive && php symfony preservation:scheduler >> /var/log/atom/scheduler.log 2>&1

preservationIdentifyTask

Identifies file formats using Siegfried (PRONOM-based identification).

Location: lib/task/preservationIdentifyTask.class.php

Namespace: preservation:identify

Options:

Option	Default	Description
`--status`	-	Show Siegfried status and statistics
`--dry-run`	-	Preview without identifying
`--limit=N`	100	Maximum objects to identify
`--object-id=N`	-	Identify specific object
`--all`	false	Identify all objects (including already identified)
`--reidentify`	false	Force re-identification of already identified objects

Usage:

php symfony preservation:identify --status
php symfony preservation:identify --dry-run
php symfony preservation:identify --limit=500
php symfony preservation:identify --object-id=123
php symfony preservation:identify --all --limit=1000
php symfony preservation:identify --object-id=123 --reidentify

Output includes:

PRONOM Unique Identifier (PUID)
Format name and version
MIME type
Confidence level (certain, high, medium, low)
Identification basis (signature, extension, container, byte match)
Warnings (if any)

preservationVirusScanTask

Scans digital objects for viruses using ClamAV.

Location: lib/task/preservationVirusScanTask.class.php

Namespace: preservation:virus-scan

Options:

Option	Default	Description
`--status`	-	Show ClamAV status and statistics
`--dry-run`	-	Preview without scanning
`--limit=N`	100	Maximum objects to scan
`--object-id=N`	-	Scan specific object
`--all`	false	Scan all objects (including previously scanned)
`--no-quarantine`	false	Don't quarantine infected files

Usage:

php symfony preservation:virus-scan --status
php symfony preservation:virus-scan --dry-run
php symfony preservation:virus-scan --limit=200
php symfony preservation:virus-scan --object-id=123
php symfony preservation:virus-scan --all --limit=500

preservationConvertTask

Converts digital objects to preservation-safe formats.

Location: lib/task/preservationConvertTask.class.php

Namespace: preservation:convert

Options:

Option	Default	Description
`--status`	-	Show conversion tools and statistics
`--dry-run`	-	Preview without converting
`--limit=N`	10	Maximum objects to convert
`--object-id=N`	-	Convert specific object
`--format=X`	-	Target format (tiff, pdf, wav, etc.)
`--mime-type=X`	-	Filter by source MIME type
`--quality=N`	95	Conversion quality (1-100)

Usage:

php symfony preservation:convert --status
php symfony preservation:convert --dry-run
php symfony preservation:convert --limit=50
php symfony preservation:convert --object-id=123 --format=tiff
php symfony preservation:convert --mime-type=image/jpeg --format=tiff --limit=100

Supported Conversions:

Source	Target	Tool
image/jpeg, image/png, image/bmp, image/gif	TIFF	ImageMagick
audio/mpeg, audio/ogg	WAV	FFmpeg
video/*	MKV	FFmpeg
application/msword, application/vnd.ms-excel, application/vnd.ms-powerpoint	PDF	LibreOffice
application/vnd.openxmlformats-*	PDF	LibreOffice
application/pdf	PDF/A	Ghostscript

preservationVerifyBackupTask

Verifies backup file integrity.

Location: lib/task/preservationVerifyBackupTask.class.php

Namespace: preservation:verify-backup

Options:

Option	Default	Description
`--path=X`	-	Path to specific backup file
`--backup-dir=X`	uploads/backups	Backup directory
`--checksum=X`	-	Expected checksum
`--all`	false	Verify all backups in directory

Usage:

php symfony preservation:verify-backup --path=/backups/backup.tar.gz
php symfony preservation:verify-backup --all --backup-dir=/backups
php symfony preservation:verify-backup --path=/backups/db.sql.gz --checksum=abc123...

preservationReplicateTask

Replicates files to backup targets.

Location: lib/task/preservationReplicateTask.class.php

Namespace: preservation:replicate

Options:

Option	Default	Description
`--status`	-	Show targets and statistics
`--dry-run`	-	Preview without replicating
`--limit=N`	100	Maximum objects to replicate
`--target-id=N`	-	Replicate to specific target
`--force`	false	Re-sync already synced files

Usage:

php symfony preservation:replicate --status
php symfony preservation:replicate --dry-run
php symfony preservation:replicate --limit=500
php symfony preservation:replicate --target-id=1 --limit=100
php symfony preservation:replicate --force --limit=50

preservationFixityTask

Runs fixity verification checks with optional self-healing auto-repair.

Location: lib/task/preservationFixityTask.class.php

Namespace: preservation:fixity

Options:

Option	Default	Description
`--status`	-	Show statistics
`--repair-stats`	-	Show self-healing repair statistics
`--dry-run`	-	Preview without verifying
`--limit=N`	100	Maximum objects to check
`--stale-days=N`	30	Check objects not verified in N days
`--all`	false	Check all regardless of age
`--object-id=N`	-	Check specific object
`--auto-repair`	false	Enable self-healing auto-repair from backups
`--failed-only`	false	Only show failed checks in status

Self-Healing Auto-Repair:

When --auto-repair is enabled, the system will automatically:

Detect failed fixity checks (checksum mismatch or missing files)
Search configured replication targets for valid backup copies
Validate backup integrity against stored checksums
Restore corrupted files from verified backups
Log all repair events as PREMIS preservation events

Supported Backup Targets:

Local file system paths
Rsync targets
SFTP servers
Amazon S3 buckets (requires AWS SDK)
Azure Blob Storage (requires SDK)
Google Cloud Storage (requires SDK)

Usage:

php symfony preservation:fixity --status
php symfony preservation:fixity --repair-stats
php symfony preservation:fixity --limit=500
php symfony preservation:fixity --object-id=123
php symfony preservation:fixity --auto-repair
php symfony preservation:fixity --stale-days=7 --auto-repair
php symfony preservation:fixity --object-id=123 --auto-repair

preservationPronomSyncTask

Synchronizes format registry from UK National Archives PRONOM database.

Location: lib/task/preservationPronomSyncTask.class.php

Namespace: preservation:pronom-sync

Options:

Option	Default	Description
`--status`	-	Show PRONOM sync status
`--puid=X`	-	Sync specific PUID (e.g., fmt/18)
`--lookup=X`	-	Look up PUID without syncing
`--unregistered`	-	Sync only unregistered PUIDs
`--common`	-	Sync common archival format PUIDs
`--all`	-	Sync all known PUIDs

PRONOM Data Retrieved:

Official format names and versions
MIME types and file extensions
Binary signature availability
Format risk information
Preservation recommendations

Usage:

php symfony preservation:pronom-sync --status
php symfony preservation:pronom-sync --puid=fmt/18
php symfony preservation:pronom-sync --lookup=fmt/43
php symfony preservation:pronom-sync --unregistered
php symfony preservation:pronom-sync --common
php symfony preservation:pronom-sync --all

preservationPackageTask

Manages OAIS packages (SIP/AIP/DIP) using BagIt format.

Location: lib/task/preservationPackageTask.class.php

Namespace: preservation:package

Actions:

Action	Description
`list`	List all packages
`create`	Create a new package
`show`	Show package details
`add-objects`	Add digital objects to package
`build`	Build the BagIt package
`validate`	Validate package checksums
`export`	Export to ZIP/TAR format
`convert`	Convert SIP to AIP or AIP to DIP

Options:

Option	Default	Description
`--id=N`	-	Package ID
`--uuid=X`	-	Package UUID
`--type=X`	-	Package type (sip, aip, dip)
`--status=X`	-	Filter by status
`--name=X`	-	Package name
`--description=X`	-	Package description
`--format=X`	zip	Export format (zip, tar, tar.gz)
`--output=X`	-	Output path
`--objects=X`	-	Comma-separated object IDs
`--query=X`	-	Object query (e.g., "mime_type:application/pdf")
`--originator=X`	-	Creating organization
`--limit=N`	20	Limit for list operations

Usage:

# List packages
php symfony preservation:package list
php symfony preservation:package list --type=sip --status=draft

# Create package
php symfony preservation:package create --type=sip --name="My Collection SIP"

# Show package details
php symfony preservation:package show --id=1

# Add objects
php symfony preservation:package add-objects --id=1 --objects=100,101,102
php symfony preservation:package add-objects --id=1 --query="mime_type:application/pdf"

# Build package
php symfony preservation:package build --id=1

# Validate
php symfony preservation:package validate --id=1

# Export
php symfony preservation:package export --id=1 --format=zip

# Convert SIP to AIP
php symfony preservation:package convert --id=1 --type=aip

Process Flows

Virus Scan Flow

+-------------------------------------------------------------------------+
|                         VIRUS SCAN SEQUENCE                              |
+-------------------------------------------------------------------------+

    +----------+     +----------------+     +--------------+
    |  Client  |     |PreservationSvc |     |    ClamAV    |
    +----+-----+     +-------+--------+     +------+-------+
         |                   |                     |
         | scanForVirus      |                     |
         | (objectId)        |                     |
         |------------------>|                     |
         |                   |                     |
         |                   | isClamAvAvailable() |
         |                   |-------------------->|
         |                   |<--------------------|
         |                   |                     |
         |                   | Get file path       |
         |                   | Verify file exists  |
         |                   |                     |
         |                   | clamscan/clamdscan  |
         |                   |-------------------->|
         |                   |<--------------------|
         |                   |    (return code)    |
         |                   |                     |
         |                   | Parse results       |
         |                   | 0=clean, 1=infected |
         |                   |                     |
         |                   | If infected:        |
         |                   |   Quarantine file   |
         |                   |                     |
         |                   | INSERT virus_scan   |
         |                   | INSERT event        |
         |                   |                     |
         |   return results  |                     |
         |<------------------|                     |

Format Conversion Flow

+-------------------------------------------------------------------------+
|                      FORMAT CONVERSION SEQUENCE                          |
+-------------------------------------------------------------------------+

    +----------+     +----------------+     +--------------+
    |  Client  |     |PreservationSvc |     | Tool (IM/FF) |
    +----+-----+     +-------+--------+     +------+-------+
         |                   |                     |
         | convertFormat     |                     |
         | (objectId, fmt)   |                     |
         |------------------>|                     |
         |                   |                     |
         |                   | Get digital object  |
         |                   | Get file path       |
         |                   |                     |
         |                   | selectConversionTool()
         |                   | (based on MIME type)|
         |                   |                     |
         |                   | INSERT conversion   |
         |                   | status=processing   |
         |                   |                     |
         |                   | executeConversion() |
         |                   |-------------------->|
         |                   |<--------------------|
         |                   |    (output file)    |
         |                   |                     |
         |                   | Verify output exists|
         |                   | Generate checksum   |
         |                   |                     |
         |                   | UPDATE conversion   |
         |                   | status=completed    |
         |                   |                     |
         |                   | INSERT event        |
         |                   |                     |
         |   return results  |                     |
         |<------------------|                     |

Replication Flow

+-------------------------------------------------------------------------+
|                       REPLICATION SEQUENCE                               |
+-------------------------------------------------------------------------+

    +----------+     +----------------+     +--------------+
    |   CLI    |     |ReplicateTask   |     |   Target     |
    +----+-----+     +-------+--------+     +------+-------+
         |                   |                     |
         | Execute task      |                     |
         |------------------>|                     |
         |                   |                     |
         |                   | Get active targets  |
         |                   | Get objects to sync |
         |                   |                     |
         |                   | For each object:    |
         |                   |   Get file path     |
         |                   |   Generate checksum |
         |                   |                     |
         |                   | INSERT log          |
         |                   | status=started      |
         |                   |                     |
         |                   | Transfer file       |
         |                   | (based on type)     |
         |                   |-------------------->|
         |                   |<--------------------|
         |                   |                     |
         |                   | UPDATE log          |
         |                   | status=completed    |
         |                   |                     |
         |                   | UPDATE target       |
         |                   | last_sync_at        |
         |                   |                     |
         |   print summary   |                     |
         |<------------------|                     |

Routes

Defined in modules/preservation/config/module.yml:

Route	URL	Action
`preservation_index`	`/preservation`	Dashboard
`preservation_identification`	`/preservation/identification`	Format identification UI
`preservation_scheduler`	`/preservation/scheduler`	Workflow scheduler UI
`preservation_schedule_edit`	`/preservation/scheduleEdit`	Create/edit schedule
`preservation_virus_scan`	`/preservation/virus-scan`	Virus scan UI
`preservation_conversion`	`/preservation/conversion`	Conversion UI
`preservation_backup`	`/preservation/backup`	Backup verification UI
`preservation_extended`	`/preservation/extended`	Extended stats

Settings routes in ahgThemeB5Plugin:

Route	URL	Action
`ahgSettings_preservation`	`/ahgSettings/preservation`	Replication target management

Configuration

External Tool Requirements

Siegfried (PRONOM Format Identification):

# Install
curl -sL "https://github.com/richardlehane/siegfried/releases/download/v1.11.1/siegfried_1.11.1-1_amd64.deb" -o /tmp/sf.deb
sudo dpkg -i /tmp/sf.deb

# Verify installation
sf -version

# Update signatures (optional)
sf -update

ClamAV:

# Install
sudo apt install clamav clamav-daemon

# Update signatures
sudo freshclam

# Start daemon (optional, for faster scans)
sudo systemctl enable clamav-daemon
sudo systemctl start clamav-daemon

ImageMagick:

sudo apt install imagemagick

FFmpeg:

sudo apt install ffmpeg

LibreOffice:

sudo apt install libreoffice

Ghostscript:

sudo apt install ghostscript

Quarantine Directory

Infected files are moved to: {sf_upload_dir}/quarantine/

Ensure this directory exists and has appropriate permissions:

mkdir -p /usr/share/nginx/archive/uploads/quarantine
chmod 750 /usr/share/nginx/archive/uploads/quarantine
chown www-data:www-data /usr/share/nginx/archive/uploads/quarantine

Conversion Output Directory

Converted files are stored in: {sf_upload_dir}/conversions/

mkdir -p /usr/share/nginx/archive/uploads/conversions
chmod 755 /usr/share/nginx/archive/uploads/conversions
chown www-data:www-data /usr/share/nginx/archive/uploads/conversions

Security Considerations

Access Control: All preservation actions require administrator role
File Access: Service only reads files within configured upload directory
Audit Trail: All operations logged as PREMIS events
Quarantine: Infected files isolated with restricted permissions
Input Sanitization: All file paths escaped for shell commands
Error Messages: Binary data sanitized before database storage

Performance Considerations

Batch Processing: Use batch operations for large collections
Scheduling: Run intensive operations during off-peak hours
ClamAV Daemon: Use clamdscan (daemon) instead of clamscan for faster scans
Conversion Queue: Process conversions in batches with limits
Indexing: All foreign keys and frequent query columns indexed

Cron Configuration

Recommended cron schedule:

# Daily format identification at 1am
0 1 * * * cd /usr/share/nginx/archive && php symfony preservation:identify --limit=500 >> /var/log/atom/identify.log 2>&1

# Daily fixity check at 2am
0 2 * * * cd /usr/share/nginx/archive && php symfony preservation:fixity --limit=500 >> /var/log/atom/fixity.log 2>&1

# Daily virus scan at 3am (new files only)
0 3 * * * cd /usr/share/nginx/archive && php symfony preservation:virus-scan --limit=200 >> /var/log/atom/virus-scan.log 2>&1

# Weekly format conversion on Sunday at 4am
0 4 * * 0 cd /usr/share/nginx/archive && php symfony preservation:convert --limit=100 >> /var/log/atom/conversion.log 2>&1

# Daily replication at 5am
0 5 * * * cd /usr/share/nginx/archive && php symfony preservation:replicate --limit=500 >> /var/log/atom/replication.log 2>&1

# Weekly backup verification on Saturday at 6am
0 6 * * 6 cd /usr/share/nginx/archive && php symfony preservation:verify-backup --all >> /var/log/atom/backup-verify.log 2>&1

Error Handling

Error	Cause	Resolution
`Siegfried not installed`	sf command not in PATH	Install Siegfried (see Configuration)
`ClamAV not installed`	clamscan not in PATH	Install: `apt install clamav`
`No conversion tool available`	Missing tool for format	Install required tool
`File not found`	Missing physical file	Check storage, restore backup
`Format identification failed`	Siegfried error	Check Siegfried installation, update signatures
`PUID showing as UNKNOWN`	Format not in PRONOM	File may have non-standard format
`Conversion failed`	Tool error	Check tool logs, verify format
`Replication failed`	Network/permission error	Check target connectivity
`Incorrect string value`	Binary in error message	Handled by sanitization

Monitoring

Key Metrics

Virus scans per day (clean vs infected)
Conversions per day (completed vs failed)
Replication success rate
Backup verification status
Fixity check pass rate

Alerting Thresholds

Metric	Warning	Critical
Infected Files (30d)	> 0	> 5
Conversion Failures (30d)	> 10	> 50
Replication Failures (30d)	> 5	> 20
Backup Verification Failures	> 0	> 0
Fixity Failures (30d)	> 0	> 10

Format Migration

Overview

The format migration subsystem enables proactive digital preservation through:

Migration Pathways: Define recommended conversion routes between formats
Migration Plans: Batch migration planning with tracking
Obsolescence Analysis: Identify at-risk formats in the repository
Automated Recommendations: Suggest target formats based on risk levels

Migration Pathway Tables

+-------------------------------------------------------------------------+
|                    FORMAT MIGRATION DATABASE SCHEMA                      |
+-------------------------------------------------------------------------+

+---------------------------+           +---------------------------+
|   preservation_format     |           | preservation_migration_   |
|    (existing table)       |           |        pathway            |
+---------------------------+           +---------------------------+
| PK id                     |<----------| PK id                     |
|    puid                   |    FK     | FK source_format_id       |
|    format_name            |           | FK target_format_id       |--------+
|    risk_level             |    +------| FK preferred_tool_id      |        |
|    ...                    |    |      |    pathway_type           |        |
+---------------------------+    |      |    confidence_level       |        |
                                 |      |    complexity             |        |
+---------------------------+    |      |    data_loss_risk         |        |
|  preservation_conversion_ |    |      |    quality_impact         |        |
|         tool              |<---+      |    is_recommended         |        |
+---------------------------+           |    is_automated           |        |
| PK id                     |           |    notes                  |        |
|    tool_name              |           |    created_at             |        |
|    tool_version           |           |    updated_at             |        |
|    ...                    |           +---------------------------+        |
+---------------------------+                      |                         |
                                                   | 1:N                     |
                                                   v                         |
                            +---------------------------+                    |
                            | preservation_migration_   |                    |
                            |      pathway_tool         |                    |
                            +---------------------------+                    |
                            | PK id                     |                    |
                            | FK pathway_id             |                    |
                            | FK tool_id                |                    |
                            |    priority               |                    |
                            |    conversion_options     |                    |
                            +---------------------------+                    |
                                                                             |
+---------------------------+           +---------------------------+        |
| preservation_migration_   |           | preservation_migration_   |        |
|         plan              |           |      plan_item            |        |
+---------------------------+           +---------------------------+        |
| PK id                     |<----------| PK id                     |        |
|    name                   |     FK    | FK plan_id                |        |
|    description            |           | FK digital_object_id      |        |
|    status                 |           | FK pathway_id             |--------+
|    created_by             |           |    source_format          |
|    approved_by            |           |    target_format          |
|    approved_at            |           |    priority               |
|    started_at             |           |    status                 |
|    completed_at           |           |    started_at             |
|    total_items            |           |    completed_at           |
|    items_completed        |           |    conversion_log         |
|    items_failed           |           |    error_message          |
|    notes                  |           |    created_at             |
|    created_at             |           +---------------------------+
|    updated_at             |
+---------------------------+

Migration Database Tables

preservation_migration_pathway

Defines conversion routes between format types.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`source_format_id`	BIGINT FK	Reference to preservation_format
`target_format_id`	BIGINT FK	Target format reference
`preferred_tool_id`	BIGINT FK	Preferred conversion tool
`pathway_type`	ENUM	normalization, migration, emulation
`confidence_level`	ENUM	high, medium, low
`complexity`	ENUM	simple, moderate, complex
`data_loss_risk`	ENUM	none, minimal, moderate, significant
`quality_impact`	ENUM	lossless, minimal_loss, noticeable_loss
`is_recommended`	TINYINT(1)	Official recommendation
`is_automated`	TINYINT(1)	Can be automated
`notes`	TEXT	Additional guidance

preservation_migration_plan

Batch migration execution plans.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`name`	VARCHAR(255)	Plan name
`description`	TEXT	Plan description
`status`	ENUM	draft, approved, in_progress, completed, cancelled
`created_by`	VARCHAR(100)	Creator
`approved_by`	VARCHAR(100)	Approver
`approved_at`	DATETIME	Approval timestamp
`started_at`	DATETIME	Execution start
`completed_at`	DATETIME	Execution completion
`total_items`	INT UNSIGNED	Total items in plan
`items_completed`	INT UNSIGNED	Successfully migrated
`items_failed`	INT UNSIGNED	Failed migrations

preservation_migration_plan_item

Individual items within a migration plan.

Column	Type	Description
`id`	BIGINT PK	Auto-increment primary key
`plan_id`	BIGINT FK	Reference to migration_plan
`digital_object_id`	INT FK	Reference to digital_object
`pathway_id`	BIGINT FK	Reference to migration_pathway
`source_format`	VARCHAR(100)	Source PUID or MIME type
`target_format`	VARCHAR(100)	Target format
`priority`	INT	Processing priority
`status`	ENUM	pending, processing, completed, failed, skipped
`started_at`	DATETIME	Item processing start
`completed_at`	DATETIME	Item processing end
`conversion_log`	TEXT	Conversion output log
`error_message`	TEXT	Error details if failed

Migration Service API

MigrationPathwayService

/**
 * Get available migration pathways for a source format.
 *
 * @param string $sourceFormat Source PUID or MIME type
 * @return array Available pathways with recommendations
 */
public function getPathwaysForFormat(string $sourceFormat): array

/**
 * Get recommended target format for a source.
 *
 * @param string $sourceFormat Source PUID or MIME type
 * @return array|null Best pathway with target format
 */
public function getRecommendedTarget(string $sourceFormat): ?array

/**
 * Get obsolescence report for repository.
 *
 * @param string $riskLevel Filter by risk (critical, high, medium, low)
 * @return array Formats at risk with object counts
 */
public function getObsolescenceReport(?string $riskLevel = null): array

/**
 * Create a new migration pathway.
 *
 * @param array $data Pathway configuration
 * @return int New pathway ID
 */
public function createPathway(array $data): int

MigrationPlanService

/**
 * Create a migration plan.
 *
 * @param string $name Plan name
 * @param string $description Plan description
 * @param string $createdBy Creator user
 * @return int New plan ID
 */
public function createPlan(string $name, string $description, string $createdBy): int

/**
 * Add items to a migration plan.
 *
 * @param int $planId Plan ID
 * @param array $items Array of [digital_object_id, pathway_id, priority]
 * @return int Number of items added
 */
public function addPlanItems(int $planId, array $items): int

/**
 * Add items by format criteria.
 *
 * @param int $planId Plan ID
 * @param string $sourceFormat Source format to match
 * @param int $pathwayId Pathway to use
 * @param int $limit Maximum items to add
 * @return int Number of items added
 */
public function addItemsByFormat(int $planId, string $sourceFormat, int $pathwayId, int $limit = 1000): int

/**
 * Execute a migration plan.
 *
 * @param int $planId Plan ID
 * @param int $limit Items per batch
 * @return array Execution results
 */
public function executePlan(int $planId, int $limit = 100): array

/**
 * Get plan execution status.
 *
 * @param int $planId Plan ID
 * @return array Status with progress metrics
 */
public function getPlanStatus(int $planId): array

preservationMigrationTask

CLI task for format migration operations.

Location: lib/task/preservationMigrationTask.class.php

Namespace: preservation:migration

Actions:

Action	Description
`pathways`	List available migration pathways
`obsolescence`	Generate obsolescence report
`recommend`	Get recommendations for a format
`plan-list`	List migration plans
`plan-create`	Create a new plan
`plan-add`	Add items to a plan
`plan-execute`	Execute a plan
`plan-status`	Show plan status

Options:

Option	Default	Description
`--format=X`	-	Source format (PUID or MIME)
`--risk=X`	-	Risk level filter
`--plan-id=N`	-	Plan ID
`--name=X`	-	Plan name
`--pathway-id=N`	-	Pathway ID
`--limit=N`	100	Items limit

Usage:

# List pathways for a format
php symfony preservation:migration pathways --format=fmt/18

# Generate obsolescence report
php symfony preservation:migration obsolescence
php symfony preservation:migration obsolescence --risk=critical

# Get recommendations
php symfony preservation:migration recommend --format=fmt/18

# Create migration plan
php symfony preservation:migration plan-create --name="TIFF Migration 2026"

# Add items to plan
php symfony preservation:migration plan-add --plan-id=1 --format=fmt/353 --pathway-id=5

# Execute plan
php symfony preservation:migration plan-execute --plan-id=1 --limit=50

# Check status
php symfony preservation:migration plan-status --plan-id=1

Migration Process Flow

+-------------------------------------------------------------------------+
|                      FORMAT MIGRATION SEQUENCE                           |
+-------------------------------------------------------------------------+

    +----------+     +----------------+     +----------------+
    |  Admin   |     |MigrationPlanSvc|     |PathwaySvc      |
    +----+-----+     +-------+--------+     +-------+--------+
         |                   |                      |
         | obsolescence      |                      |
         | report            |                      |
         |------------------>|                      |
         |                   | getObsolescence      |
         |                   | Report()             |
         |                   |--------------------->|
         |                   |<---------------------|
         |   at-risk formats |                      |
         |<------------------|                      |
         |                   |                      |
         | create plan       |                      |
         |------------------>|                      |
         |                   | createPlan()         |
         |                   |                      |
         |   plan_id         |                      |
         |<------------------|                      |
         |                   |                      |
         | add items by      |                      |
         | format            |                      |
         |------------------>|                      |
         |                   | addItemsByFormat()   |
         |                   | getRecommendedTarget |
         |                   |--------------------->|
         |                   |<---------------------|
         |                   |                      |
         |                   | INSERT plan_items    |
         |                   |                      |
         |   items added     |                      |
         |<------------------|                      |
         |                   |                      |
         | approve & execute |                      |
         |------------------>|                      |
         |                   | executePlan()        |
         |                   |                      |
         |                   | For each item:       |
         |                   |   convertFormat()    |
         |                   |   UPDATE status      |
         |                   |                      |
         |   results         |                      |
         |<------------------|                      |

Version History

Version	Date	Changes
1.0.0	2026-01	Initial release with checksums, fixity, events
1.1.0	2026-01	Added virus scanning (ClamAV), format conversion (ImageMagick/FFmpeg/LibreOffice/Ghostscript), backup verification, replication targets, CLI tasks, settings UI
1.2.0	2026-01	Added Siegfried/PRONOM format identification with PUID tracking, confidence levels, batch identification CLI task, identification UI dashboard, auto-population of format registry
1.3.0	2026-01	Added Workflow Scheduler UI for configuring and monitoring automated preservation tasks, preservationSchedulerTask CLI task, schedule management service methods, run history tracking
1.4.0	2026-01	Added Format Migration subsystem: migration pathways, migration plans, obsolescence reporting, MigrationPathwayService, MigrationPlanService, preservationMigrationTask CLI

Technical Documentation - Last Updated: January 2026 Plugin Version: 1.4.0

Contents

ahgPreservationPlugin - Technical Documentation

Overview

Architecture

Component Diagram

Database Schema

Entity Relationship Diagram

Database Tables

preservation_virus_scan

preservation_format_conversion

preservation_backup_verification

preservation_replication_target

preservation_replication_log

preservation_package

preservation_package_object

preservation_package_event

Service Layer API

PreservationService

Format Identification (Siegfried/PRONOM)

Virus Scanning

Format Conversion

Backup Verification

Extended Statistics

CLI Tasks

preservationSchedulerTask

preservationIdentifyTask

preservationVirusScanTask

preservationConvertTask

preservationVerifyBackupTask

preservationReplicateTask

preservationFixityTask

preservationPronomSyncTask

preservationPackageTask

Process Flows

Virus Scan Flow

Format Conversion Flow

Replication Flow

Routes

Configuration

External Tool Requirements

Quarantine Directory

Conversion Output Directory

Security Considerations

Performance Considerations

Cron Configuration

Error Handling

Monitoring

Key Metrics

Alerting Thresholds

Format Migration

Overview

Migration Pathway Tables

Migration Database Tables

preservation_migration_pathway

preservation_migration_plan

preservation_migration_plan_item

Migration Service API

MigrationPathwayService

MigrationPlanService

preservationMigrationTask

Migration Process Flow

Version History