Configuring SSD Cache Settings
- Go to Storage & Snapshots > Storage > Cache Acceleration.
-
Click Manage and then
select Settings.
The Switch SSD Cache window opens.
-
Select which volumes and LUNs
can use the SSD cache.
Important:
For data safety, volumes and LUNs created on an external storage device cannot use the SSD cache if the cache type is Read-write.
- Click Next.
-
Select a cache mode.
Cache Mode
Description
Recommended Use Cases
Random I/O
Only small data blocks are added to the SSD cache. Larger blocks are accessed directly from regular storage.
Virtualization, databases
All I/O
Small and large data blocks are added to the SSD cache. Both sequential and random I/O requests are accelerated.
Video streaming, large file access operations
Tip:An HDD RAID group may outperform a SSD RAID group for sequential I/O if the ratio of HDDs to SSDs is 3:1 or greater, and the HDD group has a RAID type of RAID 0, 5, 6, or 10. However, SSDs will always be faster for random I/O. If the NAS contains a RAID group of type RAID 0, 5, 6, or 10 that contains three times more disks than the SSD cache, you should select Random I/O.
- Optional:
Configure bypass block size.
This value determines the maximum size of the data blocks that are stored in the SSD cache. Selecting a larger size may improve the cache's hit rate but uses more cache space. The default value is 1 MB.
- Click Finish.