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EMC AX100 520 byte sectors

Posted: Tue Sep 13, 2016 5:58 pm
by Guest
I have an Dell/EMC AX100 with failed system board. I am attempting recovery with R-Studio virtual RAID tools. I have found that the EMC is using 520 byte sectors. Is R-Studio capable of seeing this sector size? I cannot seem to find the array parameters.

Re: EMC AX100 520 byte sectors

Posted: Wed Sep 14, 2016 9:11 am
by Alt
I don't think so. And the additional 8 bytes in each sectors should be treated not as data, but as a sort of metadata. I'm not sure any data recovery software can do that.
DATA INTEGRITY ON VNX.

Re: EMC AX100 520 byte sectors

Posted: Wed Sep 14, 2016 1:19 pm
by Corsari
Infact

When processing such special SAN storages we need to process twice the drives and sometime we need the whole storage too.

This is a recovery that can't be done DIY, sorry.

Though with a company like the one I work for, this recovery could turn to become really convenient compared to so many else that come to my mind, especially for the extensive flat rates matrix ( we have eighteen rates from as low as 150 euro per disk)

Re: EMC AX100 520 byte sectors

Posted: Wed Sep 14, 2016 2:00 pm
by Data-Medics
There's no commercial software that can work with EMC San units. Even putting aside the 520 byte sector issue, they use their own non-standard RAID algorithms. Only a few companies in the world can even handle these cases.

Let me know if you are serious about getting the data back. EMC recoveries aren't cheap as each case requires custom software to be written, but we can handle such cases: https://www.data-medics.com/emc-data-recovery/

Re: EMC AX100 520 byte sectors

Posted: Wed Sep 14, 2016 2:17 pm
by Corsari
Exact
That is the final ingredient: they use non standard algorithms and fancy combination made by sysadmin e.g. we had one EMC Clariion where they internally stacked (JBOD) a RAID5 with a RAID50 :-|

Re: EMC AX100 520 byte sectors

Posted: Wed Sep 14, 2016 2:19 pm
by RForce
I agree, definitely not a DIY recovery. Our EMC recovery engineer pretty much has to write a custom script to virtually reconstruct and recover the data from failed arrays. Not only is it expensive, it is also time consuming. The very first step you or any pro should be doing is getting a full sector-by-sector clone/image of each drive to avoid making any mistakes which might result in damaging the original drives.

If the data is important to you, I advise that you stop wasting precious time and contact one of the labs who offered to assist you.

Re: EMC AX100 520 byte sectors

Posted: Thu Sep 15, 2016 12:09 am
by Corsari
Also the task to make a sector by sector clone before to do ANY type of experiment, will result in an additional issue.

Such 520/52x bytes per sector drives won't be "read" by any common HW/SW setup.

The 52x bytes per sector is a low level preparation of the drive that makes it not properly handled by standard HWs + SWs, this situation won't allow to make a backup clone copy of every drive that is one of the "to be done" steps suggested in the tips of my signature (see at bottom)

P.S. How many drives are present in the storage? And which size are them? Which model? Do you know their interface type?

Re: EMC AX100 520 byte sectors

Posted: Thu Sep 15, 2016 8:29 am
by Alt
How often are those cases?

Re: EMC AX100 520 byte sectors

Posted: Thu Sep 15, 2016 12:43 pm
by Data-Medics
Alt wrote:How often are those cases?
Pretty rare honestly. I think we had one six months ago where a major US university lost a ton of research data when three drives in a RAID 6 failed and there were no other recent backups.

Re: EMC AX100 520 byte sectors

Posted: Thu Sep 15, 2016 12:48 pm
by Data-Medics
Corsari wrote:Such 520/52x bytes per sector drives won't be "read" by any common HW/SW setup.

The 52x bytes per sector is a low level preparation of the drive that makes it not properly handled by standard HWs + SWs, this situation won't allow to make a backup clone copy of every drive that is one of the "to be done" steps suggested in the tips of my signature (see at bottom)
It can be done in linux using most good SCSI / SAS controllers. But, certainly not a standard operation where it's going to just recognize it and mount the filesystem even if it's just a single drive formatted this way.
There is this program which claims to be able to clone 520 byte sector drives to a 512 image: http://www.datarecoveryengineer.com/har ... c-520.html

I've never tried it, so I can't say how well it works. But, even so if it's part of an EMC RAID you'd be stuck even with an image in most cases.