Is XenServer 7 an advanced format (512e or 4Kn) aware OS?

[Jason Glick]

Does anyone know for sure if XenServer 7 is compatible with AF 512e and/or 4Kn drives?  Has anyone successfully installed and used XenServer 7 on a server with advanced format drives as storage? 

 

Thank you!

[Tobias Kreidl]

No 4k drive support is currently available on any versions of XenServer, including 7.0. I have not heard about any support for the next release, either.

-=Tobias

[Jason Glick]

Is there support for 512e?  Thanks.

[Tobias Kreidl]

No, AFAIK, not 512e, either. Newer versions of vSphere and VSAN (VMware) do.

-=Tobias

[David Van Espen]

No, AFAIK, not 512e, either. Newer versions of vSphere and VSAN (VMware) do.

-=Tobias

Tobias,

 

I recently experimented with this using a simple Fujitsu TX1320M2 which had an eP400i 1GB raid card.

I made a R6 with 4 1TB 512e 7.2k drives, and installed XenServer 7 without any issues.

Also performance was like expected (tested around 250MB/s within a VM, which equals to about 2 times the transfer speed of a single disk).

 

On the other hand, I agree with you and would still never use 512e in production, and prefer the 512n 10k disks for sure.... but you CAN use them.

[Tobias Kreidl]

Interesting, thanks for the updates. I will keep pushing for future 4k support!

-=Tobias

[Willem Boterenbrood]

No, AFAIK, not 512e, either. Newer versions of vSphere and VSAN (VMware) do.

-=Tobias

 

Any system that can support 512n drives can support 512e drives. The whole idea of 512e is that a legacy system can use the newer Advanced Format drives. There might a be limit though to the maximum disk size supported on older systems.

Also using AF 512e drives can hurt performance especially with very small IO as for each 512bytes IO the disk will read/write 4096bytes so it those surrounding bytes are not used in the next IO's performance will decrease. Very often though the disk IO will involve many more surrounding bytes and only some performance is wasted. Using 4kn with a compatible OS can help as the OS is aware of the real block size on the disk.

 

When using a NAS with 4kn disks and XenServer there should be no problem as XenServer won't have to deal with the 4kn,

 

So the lack of 4kn support on XenServer only limits locally attached storage

[Tobias Kreidl]

There is also 4k boundary alignment, from what I understand.

 

Has anyone successfully attached a pooled SR with 4k drives? I've yet to hear of a single such case.

[Ben Newall]

I am currently in a position where I could really do with using 512e disks as I am about to expand my storage.

 

I need to add 4 x 2tb 10k sas 2.5" sff 512e HPE disks into one of my HP Proliant DL360p's. The biggest non 512e SFF disk compatible with this server is only 1.8tb and I need a 4tb volume (raid 10).

 

If anyone has successfully used 512e disks in a production pool scenario I would be very keen to hear about it.

 

Cheers

[Anthony Hoppe1709155106]

I just wanted to add that I'd love to see 4k sector size support in XenServer.  I just built a server with an array of 10TB disks and wanted to virtualize with XenServer to make the box more versatile.  However, I cannot utilize the array due to no 4k support in XenServer 7.2.  I am able to create the SR, but get the infamous SR_BACKEND_FAILURE_78 error when trying to utilize the SR.  Needless to say, I'm bummed.

 

I am hoping 4k sector support is on the roadmap for XenServer!

[Marc Wilhelmi]

On 20.2.2017 at 8:11 PM, Tobias Kreidl said:

There is also 4k boundary alignment, from what I understand.

 

Has anyone successfully attached a pooled SR with 4k drives? I've yet to hear of a single such case.

 

We´re testing 4k "drives"  out of a Datacore SAN at the moment. The XenServers (8.0) see a 4k fibre channel LUN and we´re able to create a SR (Hardware HBA, LVM).

But after that, we´re not able to create a VDI on that SR. No migration, no add directly in the SR-tab.

 

So I would assume that 4k support is not stable right now

[Tobias Kreidl]

I believe 512e drives may work with CH 8.0, but there is still no 4k support, AFAIK.

 

-=Tobias