Does RST help live Hyper-V VMs?

[steam2]

• I have a server with a RAID1 D: drive that includes dual 8TB HDDs. On this array I have put the server's VMs.
• The server has a RAID1 C: drive for the OS with two 256GB SSDs.
• The server also has a 120GB spare SSD.

Intel RST says it can use this spare SSD as a caching disk, with maximum size of 64GB.

Does it help the Hyper-V files, which are 100+ GB?

I was under the impression that the SSD/RST caching performance is only for files that would actually "fit" into the SSD cache, so files <64GB.

Can anyone comment on my assumption?

And is there any way Hyper-V VM files can get their speed increased?

[AP16]

In SmartResponse tech brief noted, that driver operates with data blocks, not files. So it may be not always the file should be in size of caching SSD. Although the Hyper-V works with storage via own storage driver filter, so unlikely SR/RST are capable to look into Hyper-V I/O operations.

[steam2]

Thanks for that. Specifically, I'm wondering if RST Acceleration is advantageous for caching .VHDX files? (not the contents inside the VHDX files)

[PDenn]

I am contemplating exactly the same setup as it seems to make a lot of sense for hyperV ie raid 1 for security and ssd for caching.

I was also wondering how the cache works in the event of the ssd failing ?

[Anonymous]

Hi All,

If SSD fails, the Intel® Rapid Storage Technology software will show a pop-up letting know the customer that there is an issue with the SSD. All the information is always kept in the Hard Disk Drives.

I recommend you the article: Intel® Smart Response Technology User Guide

http://www.intel.com/content/www/us/en/support/boards-and-kits/000005501.html Intel® Smart Response Technology User Guide

Regards,

Mike C

[PDenn]

Thanks for reply. I have read the guide but not very informative particularly as this is a production server, not much information about how this works and we are very concerned about data loss.

With regard to the question about HyperV if the virtual machine is using a physical disc rather than VHD would this be cached ? In order to use a physical disc that this must be off-line in windows disk management so would the IRT cache still apply ?

Also can we use IRT Raid 1 with offline disks ie would they be selectable in the IRT gui as available for acceleration?

Paul

[Anonymous]

Hi Toomanylogins,

The acceleration mode requires to be set manually through Intel® RST software and it needs to be on line always. It requires to be recognized by Windows Disk Management.

Regards,

Mike C

[PDenn]

Thanks Mike,

To Confirm as follows.

1. Intel Raid cannot be used with SSD raid 1 as trim not supported see other thread.

2. Intel RST does not support cache on SSD for Hyper V vhd

3. Intel Raid cannot be used with Offline disks therefore direct disk attach for Hyper V not supported.

In the new server I have just built now regret the choice of hardware as cant use SSD and raid 1.

Regards

Paul

[Anonymous]

Hi,

TRIM is supported in AHCI and RAID mode for drives not part of a RAID volume.

More details in the link below:

http://www.intel.com/content/www/us/en/support/boards-and-kits/000005807.html RAID Features by Chipset or Controller Hub

Regards,

Mike C