Repair a Storage Pool
Storage pool errors might occur due to various reasons, such as damaged system partitions or crashed drives. In some cases, you can follow the steps below to diagnose the error and fix the issue.
Notes:
- The Repair function described here is available only for RAID types with data redundancy (e.g. RAID 1, RAID 5, RAID 6, etc.). Please note this function does not repair broken drives, nor does it guarantee data on crashed volumes will be rescued.
- For crashed volumes, we recommend contacting our Technical Support for assistance.
- We recommend using drives in the Synology Products Compatibility List to prevent any issues. Using incompatible drives may lower the system performance or even cause data loss on your DiskStation.
Failed System Partitions
When system partitions fail, you should see a message informing you that the system partitions cannot be accessed.
To repair system partitions:
- Open Storage Manager.
- Go to Overview and click the link marked Repair. The system should repair the system partitions.
Degraded Storage Pools
A storage pool becomes Degraded when a drive fails, but data loss has not occurred. This only happens with RAID types that provide data redundancy, such as SHR, RAID 1, RAID 5, RAID 6, and RAID 10.
A degraded storage pool can be fixed by replacing the failed drive with a healthy one and repairing the storage pool.
Note:
- The size of the replacement drive must be larger or equal to the size of the smallest drive in the storage pool.
- The status of the drive for replacement must be Initialized or Not Initialized.
- SHR (Synology Hybrid RAID) is available on specific models only. For more information, please visit Synology website.
To repair a degraded storage pool:
- Go to Storage Manager > Storage Pool to confirm the status has changed to Degraded.
- If so, go to the HDD/SSD tab to see which drive has failed.
- Remove the failed drive and replace it with a new one.
Note:
- If your DiskStation does not support hot-swapping, please remember to power it off before removing and installing any drives.
- Existing data on the replacement drive will be erased.
- After the replacement drive has been installed, return to the Storage Pool tab.
- Select the degraded storage pool.
- Click Repair from the Action drop-down menu.
- Select the replacement drive which you would like to add to the volume. Then follow the instructions of the wizard to finish.
Repair Storage Pools
To repair a degraded storage pool, you need to replace the failed drive with an available drive that matches the following criteria:
- For RAID 1, RAID 5 or RAID 6 storage pools, the degraded volume can be repaired by an available drive with a size that is equal to or larger than the size of the smallest drive in the storage pool.
- For SHR-1 storage pools, the available drive must meet one of the following criteria: (1) Its size must be equal to or larger than the size of the failed drive; (2) With the largest drive in the storage pool excluded, its size must be equal to or larger than the size of the largest remaining drive.
- Example 1: SHR-1 is composed of 3TB, 2TB, 2TB, and 1TB drives. If the 3TB drive fails, it can be repaired by an available drive with a size that is equal to or larger than 2TB.
- Example 2: SHR-1 is composed of 4TB, 4TB, 2TB, and 2TB drives. If the 4TB drive fails, it can be repaired by an available drive with a size that is equal to or larger than 4TB.
- Example 3: SHR-1 is composed of 4TB, 4TB, 2TB, and 2TB drives. If the 2TB drive fails, it can be repaired by an available drive with a size that is equal to or larger than 2TB.
- For SHR-2 storage pools, the available drive must meet one of the following criteria: (1) Its size must be equal to or larger than the size of the failed drive; (2) With the two largest drives in the storage pool excluded, its size must be equal to or larger than the largest remaining drive.
If you have configured drives as hot spares that match the above criteria, they will be used for repairing the storage pool.
Resolve Crashed Storage Pools
When the status of a volume becomes Crashed, you cannot repair the volume by yourself. To solve this problem, we recommend contacting our Technical Support for help.
Before You Contact Support:
- Rescue your data on your DiskStation by copying the files to your computer or external drives via File Station, Windows File Service, FTP or other file services.
- Keep the order of the drives the same as when the volume crashed.
- Please perform an S.M.A.R.T. test on the drives with issues. To do so, go to Storage Manager > HDD/SSD and select the drive with issues and then click Health Info > S.M.A.R.T.. In the S.M.A.R.T. Test section, select Quick Test or Extended Test according to your needs and click Start to run the test.