Snapshots provide block-level protection for your data. A snapshot records the state of your data at a specific point in time. Data can then be restored to that state in the event of accidental deletion or modification.
Below are the hardware and software requirements for using snapshots on your NAS.
Your NAS hardware must support snapshots
For a list of supported models and series, see https://www.qnap.com/solution/snapshots.
Your NAS must have 4GB or more of memory
Snapshots use a lot of system memory. To ensure NAS stability, all snapshot features will be disabled on NAS with less than 4GB of memory installed.
If your NAS has less than 4GB and supports memory upgrades, then you can add more memory to enable snapshots.
Snapshots can only protect thick volumes, thin volumes, and block-based iSCSI LUNs.
Snapshots are stored in a storage pool, so only volumes, thin volumes and block-based LUNs created in a storage pool support snapshots. Snapshots cannot be used with legacy volumes, single static volumes, or file-based LUNs.
Your QTS version must support snapshots
Snapshots are supported after QTS 4.2. However, for certain ARM-based NAS series such as TS-1635, TS-831X, TS-531X, and TS-431X, support for snapshots was added in QTS 4.3.4.
If snapshots are disabled on your NAS, try updating to QTS 4.3.4 or later.
Your storage pool must support snapshots
If a storage pool is created in a version of QTS that does not support snapshots, and then QTS is updated to a version with snapshot support, the legacy pool will be unable to use snapshots. Only new storage pools created after the QTS update will have snapshot support.
To work around this issue, back up all data in the old storage pool to an external storage device, another NAS or to the cloud using Hybrid Backup Sync.
Hybrid Backup Sync can be downloaded from the App Center. For details, see https://www.qnap.com/solution/hybrid-backup-sync.
LUNs can also be backed up using LUN Backup in Storage & Snapshots. Using this feature you can export the LUN to an image file, and then later restore it as a block-based or file-based LUN.
After verifying that the backups contain a complete copy of all of your data, use “Storage & Snapshots” to delete the old legacy storage pool and create a new storage pool.
Alternatively if your NAS has any free drive bays, or if you have an expansion unit, you can add more drives to the NAS. Using these free drives, create a new storage pool and then move all data from the old pool to the new one.