What is System Reserved space?
Applicable Products
- QTS
- Storage & Snapshots
Details
QTS uses System Reserved space to store configuration information and metadata related to volumes on your NAS. Within Storage Manager and Storage & Snapshots, this space is displayed as Sys. Reserved. This space is required for proper NAS operations and consists of three different storage categories:
Category | Description | Size |
|---|---|---|
QNAP storage reserved space | Contains storage configuration data and extra space required for NAS functionality | About 70 GB for each storage pool and 20 GB for each static volume. |
QNAP RAID reserved space | Contains RAID metadata | One percent of the total capacity of each RAID group. Maximum of 150 GB per group. |
EXT4 file system metadata space | Contains metadata for the EXT4 file system | A percentage of each volume. Higher capacity volumes require less space. For volumes larger than 100 GB, space is between 0.8% to 1.8% of the volume. |
In addition to the categories listed above, System Reserved space may also include space used by Snapshot Replica. When Snapshot Replica transfers snapshots from a source NAS to a destination NAS, the system secures storage pool space on the destination for the incoming backup data. This space is accounted for under System Reserved in the storage pool usage breakdown.
The secured space corresponds to the actual storage that your backup data will occupy. Once the backup transfer is complete, this space is fully used by the transferred data. If you remove a Snapshot Vault from the destination NAS, the associated System Reserved space will be released.
As a result, a storage pool that contains a Snapshot Vault will show a larger System Reserved value compared to a storage pool without one. This is expected behavior and does not indicate a storage error.
