Xenserver 6.2 ISCSI SR

[Daniel.Furcht]

Hi, I try to connect a Xenserver 6.2 to a FreeNAS 8.3.1-RELEASE-p2.
All Seems Ok, SR is created, report no errors.
When try to create a Disk or VM in this SR, it will fail always.
Its sound like the LVM is corrupted after a write.
On logs, a "SR_BACKEND_FAILURE_46" appears...

Anyone had a similar issue ?

 

[jimp]

I have experienced this issue when I configured FreeNAS to use a 4096 iSCSI block size. XenServer (6.2) would initialize the SR, but it would never create disks on it. Additionally, actions like detaching the SR resulted in some really broken setups (attempted with a pool).

The solution was to use the default standard 512 block size and XenServer hums along fine. I haven't had other iSCSI initiators break over the 4096 blocksize, but it's probably better to use the well-tested 512 value anyway. I wasn't able to find any Citrix documentation that only 512 BS is allowed.

 

[Daniel.Furcht]

Hi, have you tried with never versions of Freenas?

 

[jimp]

Yes. I ran into the same problem/solution just last week on a 9.2.0 FreeNAS box. I originally discovered this broken setup with a 9.1 FreeNAS box. I obviously didn't learn my lesson the first time.

I'm sorry, but I cannot remember at this point if my exact error was SR_BACKEND_FAILURE_46. But the symptom was identical otherwise. The SR initialized perfectly (I assume), but was corrupted or otherwise not really usable.

 

[Daniel.Furcht]

I wait for the solution for this since Freenas 8.3. This potencially speed up the hard disk throughput. For now my 4k disks will operate in 512 byte sector emulation, big lost of performance... ;)