Raid 5 on PERC H700 (R710)

Discussions on using the professional data recovery program R-STUDIO for RAID re-construction, NAS recovery, and recovery of various disk and volume managers: Windows storage spaces, Apple volumes, and Linux Logical Volume Manager.
Prog1
Posts: 1
Joined: Wed Feb 06, 2019 6:11 pm

Raid 5 on PERC H700 (R710)

Post by Prog1 » Wed Feb 06, 2019 6:30 pm

I have a failed RAID 5 array. It has 2 failed drives out of 8.

If I try make an image of the failed drives using R-Studio using Windows how can I be sure that Windows will not try to write back to the disk when I connect it? The drive will be plugged into as Thermaltake SATA to USB hard drive adapter or direct to a SATA connector. Presumably the direct SATA connection will be faster?

Thanks, Prog1

Alt
Site Moderator
Posts: 2459
Joined: Tue Nov 11, 2008 2:13 pm
Contact:

Re: Raid 5 on PERC H700 (R710)

Post by Alt » Thu Feb 07, 2019 4:06 am

Prog1 wrote:
Wed Feb 06, 2019 6:30 pm


If I try make an image of the failed drives using R-Studio using Windows how can I be sure that Windows will not try to write back to the disk when I connect it?
I think Windows will not recognize the file system on the disk and will not write anything. At most it may suggest to initialize / format it. But it won't do anything by itself.
Prog1 wrote:
Wed Feb 06, 2019 6:30 pm

The drive will be plugged into as Thermaltake SATA to USB hard drive adapter or direct to a SATA connector. Presumably the direct SATA connection will be faster?
Yes, the direct SATA is faster.

Data-Medics
Posts: 186
Joined: Tue Oct 20, 2015 10:13 am
Location: Providence, RI USA
Contact:

Re: Raid 5 on PERC H700 (R710)

Post by Data-Medics » Thu Feb 07, 2019 8:29 am

Prog1 wrote:
Wed Feb 06, 2019 6:30 pm
It has 2 failed drives out of 8.
R-Studio is a great product for RAID recovery, the best in my opinion. However, using it to clone a "failed" drive as you say is a bad idea. At the very least the drive will have bad sectors, possibly bigger issues. Trying to clone in Windows using any program is likely to result in killing the drive off completely. R-Studio's imaging capabilities are intended for healthy drives, not failed ones.

You might think that's okay because you've got a single drive of redundancy, but you might not in reality. It's quite common that we find one drive of a RAID 5 has been offline for a year or longer and is now totally out of sync. So you may well be one failed drive away from total data loss of the array.

The best option would be to hardware image the failed drives using a professional data recovery hardware system (e.g. DeepSpar, PC-3000). Then you can use R-Studio along with the clones of the bad drives to rebuild the array. At the very least, you should clone the drives using a Linux based tool like ddrescue or hddsuperclone which can handle bad sectors more safely than is possible within Windows.

Maybe the PERC controller just went stupid and kicked the drives offline for no reason, it does happen with PERC cards sometimes, but it's better to play it safe than be sorry later.

Guest

Re: Raid 5 on PERC H700 (R710)

Post by Guest » Thu Feb 07, 2019 1:54 pm

Thanks for your helpful replies.

We are going to go for professional recovery rather than a DIY approach. Does anyone have any provider recommendations? I am in Northern Nevada, if that matters.

Thank you.

Post Reply