Features

  • The Btrfs file system can perform file self-healing to automatically detect silent data corruption and recover corrupted data (See limitation 1)
  • Powerful snapshot feature for creating point-in-time snapshots
  • SSD cache support for enhancing system performance

Specifications

General
  • File system types:
    • ext4 and Btrfs (See limitation 2)
    • For external devices: ext4, ext3, FAT, FAT32, NTFS, Btrfs, exFAT, HFS, and HFS+ (See limitation 2)
  • RAID types:
    • Basic, SHR-1, SHR-2, JBOD, RAID 0, RAID 1, RAID 5, RAID 6, RAID 10, and RAID F1 (See limitation 2)
  • RAID conversion:
    • Basic to RAID 1, Basic to RAID 5, RAID 1 to RAID 5, RAID 5 to RAID 6, and SHR-1 to SHR-2
  • Up to 512 shared folders (See limitation 2)
  • Up to 256 volumes (See limitation 2)
  • Supports creating global and dedicated hot spare drives
  • Supports expanding storage pool and volume capacity without service disruption
  • Supports creating SSD read-only caches and SSD read-write caches
  • Supports setting volume usage quota
  • Supports setting usage and user quota for shared folders in the Btrfs file system
  • Supports scheduling data scrubbing to ensure data integrity (See limitation 4)
  • Supports adjusting the data scrubbing speed limit, repairing storage pools, expanding storage pools, and changing the RAID types of storage pools
  • Supports RAID Group to improve the level of protection (See limitation 2)
  • Supports Dynamic Bad Sector Mapping to enhance data integrity during storage pool repair
  • Supports complete Windows access control list (ACL)
  • Supports encrypting shared folders with AES-256 CBC mode
Drive Management
  • Supports HDD hibernation feature for power saving
  • Supports SSD TRIM feature for sustained performance
  • Supports scheduling S.M.A.R.T. tests
  • Supports Seagate IronWolf Health Management (IHM)
  • Supports deactivating HDDs while Synology NAS is powered on to prevent service disruption
  • Supports switching the LED indicator of a specific drive slot
ext4 File System
  • Maximum single file size: 16 TiB
  • Maximum file name length: 255 bytes (See limitation 5)
  • Maximum path name length: 4,096 bytes (See limitation 5)
  • Maximum symbolic link depth: 40
  • Maximum single volume size: 200 TiB (See limitation 2)
  • Recommended maximum number of files per folder in the same level: 100,000 (See limitation 3)
Btrfs File System
  • Maximum single file size: 16 TiB
  • Maximum file name length: 255 bytes (See limitation 5)
  • Maximum path name length: 4,096 bytes (See limitation 5)
  • Maximum symbolic link depth: 40
  • Maximum single volume size: 200 TiB (See limitation 2)
  • Recommended maximum number of files per folder in the same level: 100,000 (See limitation 3)
  • Supports inline compression
  • Supports performing file self-healing to automatically detect and recover silent data corruption on metadata and data (See limitation 1)
  • Supports copying data instantly via the SMB protocol when the source and destination of the data are located in the same Btrfs volume
  • Allows manual implementation of file system defragmentation to enhance system performance
  • Integrated with Synology Drive Server and Hyper Backup to enhance storage efficiency and data consistency
Snapshots on the Btrfs File System
  • Supports taking snapshots and creating replication tasks for shared folders and LUNs
  • Maximum number of snapshots per system:
    • Memory exceeding or equivalent to 2 GB: 65,536
    • Others: 4,096
  • Maximum number of snapshots per shared folder:
    • Memory exceeding or equivalent to 2 GB: 1,024
    • Others: 256
  • Maximum number of snapshots per LUN:
    • Memory exceeding or equivalent to 2 GB: 256
    • Others: 64
  • Supports taking application-consistent snapshots
  • Supports browsing read-only snapshots
  • Supports Windows Previous Versions feature

Limitations

  1. The data checksum option must be enabled on a shared folder before silent data corruption detection can take effect (Only RAID 1, RAID 5, RAID 6, and RAID F1 support corrupted data recovery)
  2. Varies according to models (Refer to here for more information)
  3. Approximately 1 GB memory is required for listing 100 million files in a folder of the same level
  4. File system scrubbing (only supported on the Btrfs file system) and RAID scrubbing (only supported on RAID 5, RAID 6, and RAID F1) will run sequentially when data scrubbing is performed
  5. Different character encodings may contain different data sizes (e.g., a character with UTF-8 encoding may contain 1 to 4 bytes)