Synology Tiering

DSM Version

Application component

Synology Tiering

Feature

  • Automatically moves infrequently used data from local hot tier to remote cold tier based on data access or modification frequency
  • Enables administrators to configure tiering plans, which support:
    • Automatic data movement to the cold tier based on days since last access or modification as defined in tiering policies
    • Automatic data movement to the cold tier based on available storage capacity
    • Performing data movement at scheduled times
    • Including multiple shared folders to plans
  • Automatically triggers and executes data movement according to your settings once tiering plans are configured
  • Enables users to access tiered data from hot tier. Frequently accessed files are immediately moved back to the hot tier
  • Provides administrators with a centralized interface to view the storage status of each folder, remaining space, data distribution, and plan usage for both hot and cold tiers
  • Offers troubleshooting suggestions to assist with data management

Specifications

  • Requires DSM 7.3 or above
  • Requires installing Synology Tiering Vault on the cold tier
  • Only administrators can view and operate Synology Tiering and corresponding cold tier folders
  • Supports file access in hot tier via the following protocols: SMB, AFP, NFS, FTP, and WebDAV
  • Maximum number of concurrent SMB/NFS/AFP/FTP connections: 5,000
    • The actual number of concurrent connections may vary based on the Synology NAS model
  • Maximum tierable file size: 1 TB for a single file
  • Maximum tiering plans configured in the hot tier: 10
    • Each plan can include up to 10 shared folders
    • The total number of shared folders supported across all plans depends on your storage system's hardware specifications. This limit typically ranges from 10 to 30
    • Only shared folders located in Btrfs volumes can be included in plans
    • Each plan can only have 1 cold tier
  • Both hot and cold tiers require at least 1 Gbps network bandwidth, with 10 Gbps recommended for optimal performance. Daily data tiering limit depends on the network bandwidth and disk read speed on both tiers
  • Plan name rules:
    • Maximum length: 32 characters
    • Names cannot include the following characters: ! " # % & ' ( ) * + , / : ; < = > ? @ [ ] \ ^ ` { } | ~
    • The first character cannot be a minus sign or a space character
    • The last character cannot be a space
  • Tiering policies can be based on file inactivity or modification, ranging from 1 to 1800 days
  • Allows configuring tiering frequency and start time:
    • Frequency: minimum 1 day, maximum 1 week
  • Supports storing 6,000 logs
  • Data tiering behavior includes the following:
    • Once a shared folder is included in a tiering plan, data are moved at the file level
    • Eligible files are moved to cold tier as per the tiering schedule. If volume capacity tiering is enabled, and the hot storage capacity remains below the set threshold after this initial tiering, the system will then move the oldest files. This process continues until the available space in the hot tier exceeds the defined limit
    • Tiered files are moved back to the hot tier upon editing or frequent read access from the hot tier, with the following exceptions:
      • If hot tier remaining space is less than 1% or 100 GB, the file will not be moved back solely due to read access
      • Editing is prevented if the hot tier lacks sufficient space to accommodate the file
    • If hot tier usage exceeds 95%, new shared folders cannot be added to existing plans
    • Renaming a file on the hot tier does not trigger its return from the cold tier
    • If tiering fails, the system waits until the next scheduled tiering without retry attempts. Failures are logged and displayed in the status and log
    • Once a file is moved to the cold tier, structural changes made on the hot tier (such as renaming or moving the file) will not be reflected on the cold tier
    • Data tiering and retrieval increase system memory usage, potentially impacting overall performance and the access speed of tiered files
  • Quotas set for hot tier source folders include tiered data
    • Supports setting independent quotas for corresponding folders on the cold tier
  • Supports tiering shared folders located in encrypted volumes. However, the cold tier volume is not automatically encrypted
  • Synology Tiering records file access time separately. The file access time recording frequency in Storage Manager does not apply to shared folders included in tiering plans
  • The following settings from hot tier source folders are not applied to their corresponding cold tier folders:
    • Hide this shared folder in "My Network Places"
    • Hide sub-folders and files from users without permissions
    • Recycle bin settings
    • Data checksum settings
    • Shared folder quota
    • File or folder permissions
    • Advanced permissions
    • NFS permissions
  • Custom integration with selected Synology packages:
    • File Station: Administrators can view whether a file is currently in the hot or cold tier from File Station on the hot tier
    • Hyper Backup: Supports separate backups of hot and cold tier (Learn more)
    • Snapshot Replication:
      • Supports taking snapshots of both hot and cold tier simultaneously from hot tier, until either tier reaches its snapshot limit(Learn more)
      • Tiered files are not moved back to the hot tier when a snapshot is taken
      • Hot and cold tier snapshots are stored separately and locally
      • If snapshot lock and immutable snapshot are enabled on the hot tier, these functions will also be automatically enabled on the cold tier.
    • Storage Analyzer: Hot tier analysis includes tiered files; these files are not moved back to the hot tier during analysis
    • Antivirus Essential and Antivirus by McAfee: When scanning the hot tier, tiered files are excluded from the scan
    • Storage Manager: Data deduplication supports independent operation for hot and cold tiers

Limitations

  • Does not support moving files to locations other than a Synology NAS
  • Does not support copying, encrypting, or moving shared folders included in tiering plans to other volumes. It also does not support converting them to Hybrid Share folders or setting them as source/destination folders for Shared Folder Sync
  • Does not support moving automatically created cold tier folders to other volumes
  • Does not support tiering files that have path names longer than 3,000 bytes
    • Different character encodings may contain different data sizes (e.g., a character with UTF-8 encoding may contain 1 to 4 bytes)
  • By default, only administrators have read permissions for tiered files on the cold tier; general users cannot access these files directly from cold tier
  • Deleting or editing tiered files directly in cold tier may lead to file corruption. File management should be performed entirely on hot tier. If the hot tier becomes inaccessible, files can be accessed directly from the cold tier (Learn more)
  • Limitations when integrating with the following Synology packages:
    • Hyper Backup:
      • Restoring hot or cold tier separately, or restoring both to different backup time points, may cause data inconsistency or loss (Learn more)
      • Restoring files to a folder that is not the original backup source will not retain hot tier stubs, preventing access to tiered files from the hot tier
    • Snapshot Replication:
      • Does not support taking snapshots of cold tier independently
      • Does not support separate restoration of hot or cold tier
      • Does not support snapshot replication or cloning
    • Storage Manager:
      • Does not support cross-volume data deduplication
      • Does not support performing Data Scrubbing for tiered files
    • Security Advisor:
      • Does not support storing reports in the corresponding cold tier folder
    • Audio Station, Synology Photos, Universal Search, and Media Server:
      • Re-indexing in these packages or via Control Panel > Indexing Service will move tiered files of the following formats back to the hot tier: DNG, ARW, SRF, SR2, DCR, KDC, CR2, CRW, NEF, PEF, RAW, 3FR, ERF, MEF, MOS, ORF, RW2, TIFF, TIF, and PDF
    • Web Station:
      • Including the "web" shared folder, the "web_packages" shared folder, or any other web service shared folder in tiering plans may impact Web Station performance
  • Does not support including the following shared folders into tiering plans:
    • Folders included in other tiering plans
    • Hybrid Share folders
    • WriteOnce shared folders
    • Compressed or encrypted shared folders
    • Shared folders within ext4 volumes
    • Shared folders on external devices
    • Shared folders designated as team folders for Synology Drive
    • Active Backup for Business shared folders
    • Chat shared folders
    • MailPlus shared folders
    • PACS shared folders
    • Shared folders currently in use by Download Station
    • Shared folders currently in use by Container Manager
    • Shared folders synced by Cloud Sync
    • Shared folders where Synology Mail Server stores indexed mail
    • Shared folders designated as storage destinations for archived logs in Log Center
    • Active Backup for Google Workspace and Active Backup for Microsoft 365 backup destination shared folders
    • Local directory shared folders for Presto File Server Site Express tasks or Presto Automator tasks

Synology Tiering Vault

Feature

  • Allows users to assign a Synology NAS as the cold tier for a tiering plan, offloading infrequently accessed data from the hot tier to the cold tier

Specifications

  • Requires a Synology NAS model that meets the following requirements:
    • DSM 7.3 or above
    • Minimum 2 GB RAM
    • At least 1 Gbps network bandwidth, with 10 Gbps recommended for optimal performance. Daily data tiering limit depends on the network bandwidth and disk read speed on both tiers
  • Synology Tiering Vault must be installed on the cold tier, and the corresponding Synology Tiering package installed on the hot tier
  • Cold tier volume must be in the Btrfs format
  • When a tiering plan is created, a corresponding shared folder named "Tiered_[source folder name]" is automatically generated in the cold tier
  • Only administrators group users can view the corresponding cold tier folders and tiered files

Limitations

  • Deleting or editing tiered files directly in cold tier may lead to file corruption. File management should be performed entirely on hot tier, unless the hot tier becomes inaccessible (Learn more)
  • Renaming a source shared folder or moving tiered file stubs on the hot tier will not automatically update the corresponding cold tier folder's name or location
  • File or folder permissions set in the hot tier will not transfer to the cold tier