• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 670
  • Last Modified:

VMWare Datastore on Dell array - HELP!!!

Hi - We have a Dell server with 6 internal disks running VMWare ESXi 3.5.
First two disks are a mirrored pair holding the VMWare install and initial datastore
Second 4 disks are a RAID-5 array holding the actual VM machines.
1 disk of the 4 in the RAID-5 array failed (position 3) and the server kept on running as intended.
We replaced the disk in position 3 but it failed to light up or show in the BIOS.
We tried disk 4 in position 3 with the same effect so we concluded that the position was faulty.
Despite the RAID being degraded we should still be able to boot and run whilst we get a replacement backplane or whatever ... HOWEVER ... VMWare now reports that the second disk (the array) is blank and the VM's held on it appear to be gone.
Any advice please ? We have not initialised the disks although we have deleted and recreated the array from the BIOS. The BIOS does now see the array as working but degraded which is correct.
0
andyhines
Asked:
andyhines
  • 5
  • 2
  • 2
  • +2
1 Solution
 
za_mkhCommented:
RAID 5 can only tolerate 1 disk failure! By moving Disk 4 to Disk 3, you may have confused your SCSI controller. Deleting and recreatring the array also make you lost all your data, as all disks assigned to that array are 'cleared' ..
Hope you have backups! Good luck
0
 
za_mkhCommented:
What poor English ... let me try again
 
RAID 5 can only tolerate 1 disk failure!
By moving Disk 4 to Position 3, you may have confused your SCSI controller.
Additionally, deleting and recreating the array will also make you lose your data on the disks in the array as all disks assigned to that array are 'cleared'
Our HP Servers always do that!
Hope you have backups! Good luck
0
 
vmwarun - ArunCommented:
As you have correctly pointed out, RAID-5 arrays can withstand a single drive failure in the array.

Does your Server support hot swapping ot Hard Disks ?

Please update your Server model too.
0
Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

 
za_mkhCommented:
Arunraju ... server model is irrelevent ... deleting and recreating array volume is enough to lose all data on disks. There must be a recovery model / software for this ... but I fear original poster is better off with reverting to backups if he has them..
0
 
andyhinesAuthor Commented:
We don't have backups because it was not a production server.
We *are* kicking ourselves right now.
If the array has been 'cleared' then why does the BIOS still see it as a valid but degraded array ? Surely that implies that it is aware of it as a valid array with data on it ?

Andy
0
 
za_mkhCommented:
I think it is showing as degraded because like you mentioned earlier, you said it had 4 disks, and you've recreated the array with 4 disks again, but position 3 is faulty ... well that's my take.
I hope the VM's weren't production! :-( I feel your pain!
0
 
za_mkhCommented:
I don't know if software like this works ...
 http://raid-5-data-recovery.qarchive.org/
 
0
 
vmwarun - ArunCommented:
za_mkh - Thanks for the tip.


0
 
Paul SolovyovskySenior IT AdvisorCommented:
If you have another server to put the raid set in it may be worth a try.  The parity is written both on the raid controller and the hard drives.  We have been able to recover raid set in the past this way.
0
 
InterservCommented:
Sometimes Vmware will re-key a volume and it thinkgs that the datastore is a snapshot from the SAN and doesn't display the volume in VMware, which could be why you see it in the bios and not in VMware.  The following KB should help if this is the case.  Good Luck

http://kb.vmware.com/kb/9453805
0
 
andyhinesAuthor Commented:
Unfortunately we weren't able to recover the data despite trying everyone's suggestions. Za_mkh gave the quickest and greatest quantity of answers so I am awarding the points
0

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

  • 5
  • 2
  • 2
  • +2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now