ESXi 5 Raid 50 Storage

[MaykelR]

Hello,

I am installing a new ESXi 5 server wich we are going to use as our backup target/archiving server. It is a DL180 with 12 3TB sata disks connected to a p410 sas controller.

I wanted to create 2x RAID 50 set (6 disks each) with an effective storage of +/- 12TB per set. For some reason this does not works and i cannot find the reason why.

When i try to create the VMFS-5 datastore i don't get the choise to format the disk array, and it does not see any partition on the array. I also get the following error message: Call "HostDatastoreSystem.QueryVmfsDatastoreCreateOptions" for object "ha-datastoresystem" on ESXi. When i try to partition the disk array myself true fdisk in true a ssh shell i can only create a 2TB partition however it does work tho.

I also tried creating the same set only then in RAID 5 i then have +/- 15TB available. This does work, i do get the option to format and partition the disk set true the vsphere client.

Any clues what can go wrong here ?

Thnx in advance for the answer.

Maykel.

[a_p_]

Welcome to the Community,

unfortunately there's a known issue with the cciss driver in ESXi 5.0, which prevents from using LUNs larger than 2TB minus 512 Bytes. You'll find the deails at http://kb.vmware.com/kb/2006942

André

[MaykelR]

Hello André,

Thank you for your reply, however this issue seems to be the likely cause i am a bit doubtfull. Because when i configure the controller to have a raid 5 set all seems fine and i can format the full 13,64 TB and also create a VMFS of that size. When i configure the raidset to use raid50 i do not get the option to format the disk and can only format it manualy to 2TB.

So if its a driver issue it does not really explain why raid5 works and raid50 does not.

Thnx in advance.

[a_p_]

... and also create a VMFS of that size

That's indeed a bit strange. However, I still think this may be caused by the driver. In the past (vSphere 4 and before) it was possible to present LUNs larger than 2TB. However the LUN size got divided by 2TB (due to the 2TB overflow) and a datastore with the remaining size (e.g. 1TB with a 5TB LUN) could be created, but only if the remaining size was larger than the minimum size for a VMFS datastore. So there's a slight chance that the result of 12TB modulo 2TB is smaller than the minimum VMFS size and therefore the wizard does not allow to format the LUN.

I can't prove the above, but this is what I think might happen.

André

[MaykelR]

Ok strange indeed, in both cases i do see the logical volume however in the raid50 instance i am unable to format it through the wizard, it does not give me the option either, but through the ssh console i can and then a max size of 2TB so in this case the KB seems to fit.

When i create a raid5 disk set i have the exact oposite of the KB, i see the logical volume and it gives me the option to format the drive for the complete size of 13.xTB and create a VMFS-5 datastore of 13.xTB. So here does the KB not fit.

So it cannot be in the driver since (i presume) both in raid50 or raid5 it will use the same driver. I however did use the HP ESXi 5 image maybe there is a different driver inside to explain why i do not have the problem with raid5 but that would suggest the issue is caused by the difference in the raid configuration which inturn would also be strange and would point to a controller issue.

Any other thoughts would be appreciated.