Raid50 on Dell Equallogic PS4100E

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Expand view Topic review: Raid50 on Dell Equallogic PS4100E

Re: Raid50 on Dell Equallogic PS4100E

by Peter » Thu Mar 14, 2019 10:42 am

Data-Medics wrote: Thu Mar 07, 2019 4:29 pm They're quite complex and require custom software (as in actually customized for each case).
I agree on complexity, but if software is written correctly, then you don't need to customize it for every case, as long as it's the same SAN breed.
All that requires a lot of R&D, and I doubt it would be ever available as a commercial software.

We do have support for the following SAN systems: Dell EqualLogic, Dell PowerVault, NetApp, EMC (Clariion, VNX, VNXe, VNX2), HP MSA 2040, Synology, QNAP, Drobo (yes, Drobo is a SAN-like system, which is crazy).

Re: Raid50 on Dell Equallogic PS4100E

by Data-Medics » Thu Mar 07, 2019 4:29 pm

addelop wrote: Thu Oct 04, 2018 10:43 am Hi Data-Medics,
our partition was "raw lun mapped" via vmware to an Linux host (ext3). I mapped this device 2 times in different vm clusters (its no possibile to do this on the same cluster :-)) because I confused "partition" for production environment with "partition" for test environment.
After partition operations (delete, create, quick-format) our NAS reports that the partition is free so any scan via iSCSI only gives "null" values, thats why I decided to connect drives directly and make images of them. It's the only way the see what is really on the drives.
Auto-detect works but not as expected so I'm trying to detect manually the RAID configuration.
Do you have ever recovered data from PS4100E? Can you give us professional remote assistance for data-recovery with r-studio?
We need to recover DICOM images (medical images) so even raw files are ok but we need to put togheter correctly raid5 and raid0 streams.
We also have many of our data saved in our backup so maybe it is possibile to search and se how the same data was saved/distribuited on Equallogic.
Best regards
Hey, so sorry, I never noticed this reply. SAN units are not something we can do remotely with R-Studio. They're quite complex and require custom software (as in actually customized for each case).

I'd assume by now you've already given up or sent this somewhere.

Re: Raid50 on Dell Equallogic PS4100E

by Peter » Mon Mar 04, 2019 5:37 pm

I guess it's too late, but just to clarify.

Dell EqualLogic boxes are true SANs, i.e. all data is slices by blocks and spread across the whole raid.
you can't assemble the volume w/o parsing that SAN metadata, which is not supported by any commercial software.

I know only 3 DR company who really can do it, others just outsource cases to them.
if you still need the data - pm.

Re: Raid50 on Dell Equallogic PS4100E

by addelop » Thu Oct 04, 2018 10:43 am

Hi Data-Medics,
our partition was "raw lun mapped" via vmware to an Linux host (ext3). I mapped this device 2 times in different vm clusters (its no possibile to do this on the same cluster :-)) because I confused "partition" for production environment with "partition" for test environment.
After partition operations (delete, create, quick-format) our NAS reports that the partition is free so any scan via iSCSI only gives "null" values, thats why I decided to connect drives directly and make images of them. It's the only way the see what is really on the drives.
Auto-detect works but not as expected so I'm trying to detect manually the RAID configuration.
Do you have ever recovered data from PS4100E? Can you give us professional remote assistance for data-recovery with r-studio?
We need to recover DICOM images (medical images) so even raw files are ok but we need to put togheter correctly raid5 and raid0 streams.
We also have many of our data saved in our backup so maybe it is possibile to search and se how the same data was saved/distribuited on Equallogic.
Best regards

Re: Raid50 on Dell Equallogic PS4100E

by Alt » Thu Oct 04, 2018 10:09 am

Data-Medics wrote: Thu Oct 04, 2018 9:34 am I'm not sure what Alt is referring to in saying to only build a RAID 5, as with RAID 50 you most definitely need to build a RAID 0 of two RAID 5's (perhaps he's just referring to the autodetection).
Arrrh! I always mix up RAID 0 and 1. Forget about my advice, mea culpa!

Re: Raid50 on Dell Equallogic PS4100E

by Data-Medics » Thu Oct 04, 2018 9:34 am

I'm not sure what Alt is referring to in saying to only build a RAID 5, as with RAID 50 you most definitely need to build a RAID 0 of two RAID 5's (perhaps he's just referring to the autodetection).

However, if, as you say it was only the partition that was deleted and the hardware RAID was never broken (e.g. you did it all in Windows not the RAID BIOS), then you can just scan the virtual disk as if it's a single drive and all the striping should be the same.

It's only if you actually broke the RAID (e.g. trying to re-create it in the RAID utility or RAID BIOS) that you'd need to reconstruct the RAID in R-Studio.

Re: Raid50 on Dell Equallogic PS4100E

by Alt » Wed Oct 03, 2018 6:16 am

The tip is the following:
As nothing wrong has happened with the RAID itself, only with the partition over it, you don't have to create a RAID50. One RAID 5 would suffice. Then try to use Autodetect for correct RAID parameters, as it seems that the problem with them.

Re: Raid50 on Dell Equallogic PS4100E

by addelop » Tue Oct 02, 2018 10:52 am

I have deleted, ricreated and quick-formated a partition on this SAN, Dell says there is no way to recover data and they don't give any assistance or information on array parameters. I only know that it was an Raid50 array.
Currently I'm trying with 2 virtual RAID5 each with 5 images (left sync., parity delay 2, first 2, numbers of rows 10, block size 64kb), this two
raid5 array are combined into another virtual raid0 array.
I have found many raw files with my data but they are splitted and I get this error:
"Unexpected MFT record xxx at xxx. If you are ..."
During scan.
Any tip?

Re: Raid50 on Dell Equallogic PS4100E

by Alt » Tue Oct 02, 2018 10:33 am

What is the trouble?

Raid50 on Dell Equallogic PS4100E

by addelop » Tue Oct 02, 2018 9:09 am

Did somebody have experience with Raid50 on Dell Equallogic PS4100E.
I'm in troulbe with rebuilding this array on R-studio.

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