This article provides the common reasons for volume crashes and offers methods for prevention. If your volumes have already crashed, you should refer to this article to troubleshoot the issue.

Some of the most common reasons that may cause a volume to crash are:

• The number of drives removed from a RAID configuration exceeded the maximum drive fault tolerance. This could be caused by any the following:
  • Drives were removed from a RAID configuration due to drive errors.
  • Drives were accidentally removed from the drive bays due to human error.
  • An SSD read-write cache has crashed.¹
• File system errors could be caused by the following reasons:
  • Improper system shutdown
  • Installation of non-Synology memory modules
  • Drive errors²
• A Btrfs volume was migrated to a Synology NAS that does not support the Btrfs file system.³

Only use compatible drives

When creating volumes or SSD caches, using the drives listed on the Synology Products Compatibility List can ensure system stability. If you are using any incompatible or unverified drives, we strongly suggest you replace them with compatible drives. To view compatible drives for your Synology NAS model, follow the steps below:

1. Go to the Synology Products Compatibility List.
2. Go to the Search by Synology Product tab.
3. Select your Synology NAS model from the Find your Synology product drop-down menu.
4. Select "HDD/SSD" from the Select Category drop-down menu.
5. Click Find Devices.

Run data scrubbing periodically

Data scrubbing is a data maintenance feature that amends data in storage pools that are incorrect or incomplete. We recommend performing data scrubbing twice a year to ensure data consistency and avoid data loss in the event of a drive failure.

Set up hot spare drives

A hot spare is a standby drive. When a drive crashes and results in storage pool degradation, the hot spare drive can automatically take the place of the defective drive. This allows the storage pool to repair itself and return to a healthy status in a shorter amount of time.

Do not install non-Synology memory modules

If a non-Synology memory module is installed in your Synology NAS, it could result in file system errors and lead to a volume crash. Therefore, we recommend installing the Synology memory modules listed here. You can also refer to this article to run a memory test to make sure that the installed memory modules are working properly.

Enable UPS support

If you enable UPS (Uninterruptible Power Supply) support, your Synology NAS will continue to operate for a short period of time when a power failure that results in a volume crash occurs. We recommend using the UPS listed here.