I have been looking at different approaches for speeding up RAID access. There is some good info on PrimoCache here. My goal is to establish a RAID array with a SSD perfomance cache and then have a seperate drive(s) for backups. I used Intel RST for RAID 5 and RAID 0.
See attached for full review:
So all this seems pretty fantastic, right? What’s the catch, you might ask? Setting Enable Defer-Write brings considerable risk to data integrity. All these deferred writes have to be done at some point. That some point will be when you shut down / reboot if the RAID 5 drives are so slow that they cannot sync up. At the rates on these drives I tested with, I saw it take 30-45 minutes to sync up a large copies like I did with the testing. So this is not a realistic solution for me with these drives.
The data risk comes if you have an unstable overclock, faulty drivers, misbehaving applications or anything else that will give you a BSOD or cause your system to hang/not shutdown in an orderly fashion. This causes corruption and data loss. (During testing on ReFS, I powered off during the write at shutdown. The entire volume was corrupted and the filesystem was made labelled “RAW.” - Yikes!) The required shutdown/reboot time must be well understood to ensure UPS power will give sufficient time to flush all cache to disk given a power outage.
Obviously a cache sync is required prior to performing any backup. Need to see if there is a commandline option for that to ease scripting.
Verdict? Jury is still out for me. I want to use this solution, but I plan to do more testing with my faster drives to see if this can be made a workable solution with a shutdown that doesn’t take too long. If I cannot easily automate sync for backup scripting that would also be a concern.
RAID + PrimoCache.docx (2.58 MB)