Raid50 on Dell Equallogic PS4100E

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addelop

Raid50 on Dell Equallogic PS4100E

Post 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.

Alt
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Re: Raid50 on Dell Equallogic PS4100E

Post by Alt » Tue Oct 02, 2018 10:33 am

What is the trouble?

addelop
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Re: Raid50 on Dell Equallogic PS4100E

Post 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?

Alt
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Re: Raid50 on Dell Equallogic PS4100E

Post 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.

Data-Medics
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Re: Raid50 on Dell Equallogic PS4100E

Post 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.

Alt
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Re: Raid50 on Dell Equallogic PS4100E

Post 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!

addelop
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Re: Raid50 on Dell Equallogic PS4100E

Post 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

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