• High performance and reliable storage solutions for virtualization environments
  • Intuitive iSCSI service management and monitoring
  • Virtualization certifications including VMware® vSphere, Microsoft® Hyper-V®, Citrix® XenServer, and OpenStack Cinder


  • Maximum iSCSI targets: 256 (See limitation 1)
  • Maximum LUNs: 512 (See limitation 1)
  • Maximum snapshots per LUN: 256 (See limitation 1)
  • iSCSI LUN Clone/Snapshot (See limitation 2)
  • Two types of space allocation: Thin Provisioning and Thick Provisioning
  • iSNS (Internet Storage Name Service)
  • Customizable I/O queue depth
  • Low-capacity protection mechanism
  • LUN Defragmentation to improve LUN performance
  • Online LUN capacity expansion
  • CHAP and mutual CHAP authentication
  • Access control by IQN
  • CRC Checksum for checking for errors that occur during data transmission
  • Schedulable snapshot tasks with custom retention policies
  • Supports VMware VAAI features:
    • Thin Provisioning Stun
    • Hardware Assisted Locking
    • Full Copy
    • Block Zero
  • Supports Windows ODX
  • Supports space reclamation
  • Supports assigning network interfaces to provide iSCSI services
  • Snapshot Replication: Offsite snapshot replication and recovery
  • Synology Hyper Backup: Scheduled tasks to back up LUNs to local shared folders, external devices or another Synology NAS
  • Snapshot Manager for VMware/Windows: Application-consistent snapshots
  • Synology High Availability (SHA): Ensures the reliability of LUN and iSCSI services
  • Synology SMI-S Provider: Allows administrators to manage Synology NAS as a storage device via centralized user interface of SCVMM
  • VMware Site Recovery Manager: Allows administrators to enable disaster recovery directly via VMware vCenter Server, simplifying complicated configurations and optimizing the process


  1. The maximum number of LUNs, targets, and snapshots varies according to models (Refer to the software specifications of your Synology products)
  2. iSCSI LUN Clone/Snapshot are only available on specific models (Refer to the software specifications of your Synology products)
  3. Hardware-Assisted Data Transfer, snapshots and space reclamation are not supported on Thick Provisioned LUNs
  4. Only Thin Provisioned LUNs created on Btrfs volumes on DSM 6.2 and above versions support instant snapshot and restoration
  5. Maximum number of concurrent LUN backup tasks: 1
  6. Minimum LUN size: 1 GB
  7. Minimum legacy advanced LUN size on ext4 volumes: 10 GB
  8. Defragmentation is only supported on Thin Provisioned Btrfs LUNs
  9. LUNs with the snapshot feature enabled or legacy advanced LUNs can be cloned quickly only within the same volume
  10. Converting legacy advanced LUNs will also delete the snapshots of the LUNs
  11. Discovery with CHAP authentication is not supported
  12. Only legacy advanced LUNs support three modes for space reclamation
    • Prioritize I/O Consistency
    • Balanced
    • Prioritize Reclamation