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Re: Problem with Smart Array 642 & Raid 1 [URGENT]

 
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Martin LEE_4
New Member

Problem with Smart Array 642 & Raid 1 [URGENT]

Hi all,

We have a RAID 1 on an ML350 server, someone accidently erased the logical disk on the Smart Array 642 Controller setting during bootup and now there is no logical drive in the setting.

If we put in the 2 mirror HDD now and recreate the logical drive, does it mean all the data will be gone?

Just wondering if there is anyway we can recover the data?

This is very urgent and critical in our situation, please help and any input welcome.

Thanks.
9 REPLIES 9
Rob Leadbeater
Honored Contributor

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

Hi,

I'm fairly certain that there's no way back.

Hopefully the someone who accidentally erased the logical disk, remembered to take a backup.

I'm intrigued how someone could do this. From what I recall, the warnings when you delete a logical disk are fairly clear.

Cheers,

Rob
Martin LEE_4
New Member

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

Yes there was backup done, but I was just wondered how it works.

For example, in my situation, 1 RAID controller with a single mirror, if the RAID controller goes faulty, even if I have a new card I still can't restore the data. I will have 2 useless mirror drives and everything will need to restore from backup.

So what's the point of fault tolerance in this case?
e4services
Honored Contributor

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

We have had luck with the old NetRAID SCSI controller restoring the RAID by hand. We just ignored the prompts to "Initialize" the newly created RAID set. At that point we just restarted the server. it seemed all the formatting that was needed remained on the drive, and all the data came up as accessable
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kris rombauts
Honored Contributor

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

Martin,


not sure if your last reply was still an attempt to recover your data or was it a general question on how to recover your data if a Controller goes faulty ?

If it is the latter, then there is no problem at all to recover the data because the array and logical disk information is written on the hard disks themselves, so this means that in case your controller needs to be replaced, the new controller will detect that he has no config and he will read the config from the disks and copy that into it's nvram and you'll have all data back, no problem.

What you could try to do in your case now where the raid1 array was deleted, is to re-create the mirror again with exact the same parameters (stripe size etc etc).


HTH

Kris

Martin LEE_4
New Member

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

Thanks for the reply guys.

To e4services: I have tried this but seems like it doesn't work on the Smart Array 642..

TO Kris: I have taken Rob's advise to restore from backup but I was just very curious about the point of having this particular FT strategy.

I have read about the data is store on the HDD as well. But when I tried to put the mirror on the controller, it just can't read the data and the selection were either create a new logical disk or the HDD's are unusable.

kris rombauts
Honored Contributor

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

Martin,

in your scenario that is normal, in case of a controller failure, the metadata of the raid config is read into the 'new' controller and off you go, no data loss at all.


The Netraid from the Netservers days indeed works differently and allows better recovery in those cases since you can really skip the initialize step after simply re-creaing the array/logic drives.

Kris
Martin LEE_4
New Member

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

Thanks Kris, that sounds right.

And by that, in my case, if I really need to restore it, I can just put it onto a new controller and it should read from the HDD and all the data would still be available?
kris rombauts
Honored Contributor
Solution

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

not in your case since the raid array /logical drive in formation has been erased.

So you need to re-create the raid1 array in ORCA utility first (off line with F8 at bootup) or via the SmartStart cd and then follow the restore procedure for the type of backup you made.

Kris
Martin LEE_4
New Member

Re: Problem with Smart Array 642 & Raid 1 [URGENT]

Hi Kris, thanks for making it clear, I will keep that for future reference.

Cheers
Martin