Enabling write back cache - H710P, Server 2012r2

Question

I run a T320 here at home, configured as follows: Supplied H310 card runs 2 SATA drives in a RAID1 (OS drive) A second H710P card runs an 8-disk array (RAID6), and it's this card I'm interested in. The box does file/print for our home network, plus some basic media services, and it also has a few VMs running, for various purposes - not overly heavily loaded. I've noticed a fair bit of disk thrashing and in checking the H710P's settings, it's write cache is set to write-through. I'd prefer to set it as write-back, to leverage better performance out of the array. However, when I check the OS' settings for the array's assigned drive, it is set to write-back... I'd have thought that the controller would control the disks under-pinning the array completely independently of what the OS was doing, but am wondering what - if any - 'interaction there is between the OS' cache policy, and that set for the controller itself. Obviously, the H710P has a (healthy) BBWC, and the Server itself has two redundant PSUs, each plugged into a different UPS, so performing cached writes in the event of a power outage and gracefully shutting down the machine shouldn't be an issue... Do I disable write caching within the OS, and set write-caching 'on' on the controller, or...?

DELL-Chris H · Answer

On-The-Move,

You would configure the cache setting under Virtual Disk Management page in the controller BIOS. Now to clarify, did you see that the H710 cache is showing as Write Through from the OS? The reason being is all RAID volumes are presented as Write-Through to the operating system (Windows and Linux) independent of the actual write cache policy of the virtual disk. So access the controller BIOS and verify it there.

Let me know what you see.

PowerEdge Hardware General

Was this post helpful?