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Old 10-07-2007, 10:11 PM   #1
DreamerX
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how to retrieve data from broken RAID5


Hi,
I would like to know is there a way to retrieve data from a broken RAID 5 HDDs? My situation is described as below.

Hardware Configuration:
- two Opteron processor
- 4GB RAM
- one RAID controller: LSI MegaRAID 150-6
- HDD: 3x 250GB (in RAID 5 mode)

Situation:
- the server is installed with SUSE10.0 and the system hang.
- the server then force to hard reset and found the OS corrupted very badly.
- the team decided to reinstall the OS so to power up the system asap, by replacing a new set of HDDs.
- the 'old' set of HDDs then move to the other server (with same hardware config) to perform data recovery, but the HDDs accidently re-initialized in the RAID controller BIOS.
- after that, the whole set of HDD cannot boot any more and even the SUSE rescue disk can't find the entire array.

Therefore, does anyone know the way to retrieve the data? Or is the data is completed lost?

thanks a million for any advise.
 
Old 10-08-2007, 10:59 AM   #2
farslayer
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There are commercial companies that may be able to recover the data.. very very expensive. I think my last quote for a 6 Drive 1 TB RAID 5 array recovery started at $20,000.00


You could also try contacting LSI to see if they can tell you how to get the controller to re-read/recreate the proper information from the drives to get the array back.. The system should have allowed you to import the RAID configuration instead of re-initializing the array.


Quite honestly at this point I would suggest doing a restore of the data from your most recent backup.
 
Old 10-10-2007, 09:52 AM   #3
DreamerX
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Quote:
Originally Posted by farslayer View Post
There are commercial companies that may be able to recover the data.. very very expensive. I think my last quote for a 6 Drive 1 TB RAID 5 array recovery started at $20,000.00


You could also try contacting LSI to see if they can tell you how to get the controller to re-read/recreate the proper information from the drives to get the array back.. The system should have allowed you to import the RAID configuration instead of re-initializing the array.


Quite honestly at this point I would suggest doing a restore of the data from your most recent backup.
thanks, farslayer.
i think there is no choice for this. will approach LSI for the final hope. thanks again for the advice..
 
Old 10-16-2007, 07:05 AM   #4
archtoad6
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2 Q's & a comment:

Is this a true hardware RAID (as opposed to "fake RAID") controller? -- Nothing I found on the 'Net, not even on their own site, definitively answers this Q.

It would be be helpful if you supplied one or more links to pertinent info. when asking Q's about hardware.

Have you examined the disks w/ dd or other low level tool? Perhaps w/ a live CD.
 
Old 10-17-2007, 06:41 AM   #5
DreamerX
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Quote:
Originally Posted by archtoad6 View Post
2 Q's & a comment:

Is this a true hardware RAID (as opposed to "fake RAID") controller? -- Nothing I found on the 'Net, not even on their own site, definitively answers this Q.

It would be be helpful if you supplied one or more links to pertinent info. when asking Q's about hardware.

Have you examined the disks w/ dd or other low level tool? Perhaps w/ a live CD.
Hi,
Thanks for the advise.
Here is the link for the LSI RAID card ( http://www.lsi.com/storage_home/prod...506/index.html ).
I don't remember the site but it did mentioned that this RAID controller is a hardware RAID.
I did not check the method you mentioned, but will give a try tomorrow
Anyway, thanks for the advice
 
Old 10-17-2007, 12:18 PM   #6
Zyglow
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When the drives were placed in the recovery server, where they put back in the correct order? I don't have a lot of experience using SATA raid cards, but with SCSI if the drives are out of order the controller will not see the original volume. The disks should still have the data as long as they have not been repartitioned or formatted.
 
Old 10-20-2007, 07:08 AM   #7
archtoad6
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From http://en.wikipedia.org/wiki/RAID#Hardware_RAID

Quote:
Hardware implementations provide guaranteed performance, add no overhead to the local CPU complex and can support many operating systems, as the controller simply presents a logical disk to the operating system.
. . .

Inexpensive RAID controllers have become popular that are simply a standard disk controller with a BIOS extension implementing RAID in software for the early part of the boot process. A special operating system driver then takes over the raid functionality when the system switches into protective mode.

Because these controllers often try to give the impression of being hardware RAID controllers, they are generally known as Fake RAID.[1][2][3][4][5] They do actually implement genuine RAID; the only faking is that they do it in software.
My impression, possibly erroneous, is that the need for drivers is a tell-tale sign of Fake Raid.

How much did this card cost & where was it purchased?

Dis you have any luck contacting LSI?
 
Old 10-22-2007, 04:49 PM   #8
RHELL
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If I understand you properly, you have the data you want on disks you have moved to a new system, and want to make them usable.
Ordinarily, I'd say get the LSI config tool at boot (ctl-S usually) and tell it to recover 'foreign-config', which will find the RAID tags writted to the disks and re-assemble the array...though they may need to be in order, as mentioned above. If it has already been re-initialized, this option will likely no longer exist.

From the sound of it, the poweroff may have caused problems at the fs level, so recovering the RAID will only get you back to where you were on the other server. Then you will have to use an appropriate tool to try to put the fs back in order. Not sure which fs you are using
I have heard of gradual corruption problems with older LSI RAID cards, but not all at once.

Last edited by RHELL; 10-22-2007 at 04:51 PM. Reason: clarity
 
Old 11-07-2007, 01:26 PM   #9
archtoad6
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DreamerX,
Did you find a solution? . . .
What is it?
 
Old 11-08-2007, 09:37 AM   #10
DreamerX
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Thumbs up

Quote:
Originally Posted by archtoad6 View Post
DreamerX,
Did you find a solution? . . .
What is it?
Hi,
I find there is no solution for this. Because when I perform fdisk and it printed there is no partition for the array. So, I think the MBR should be overwritten by the RAID card during initialization.
Anyway, my teammate has give up on the recovery and keep going on other works.

thanks and appreciated your support.....
 
  


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