NAS Synology problem raid6

[MasterOfpuppets]

Hi all.
I have a NAS Synology 8 disks. Was assembled as Raid6.
Due of hardware issue 2 disks failed and completely unrecoverable. I was able to reconstruct array , using original parametres. I see BTRFS in there and many strange files with abnormal sizes (more than allocated space) . There was couple of VMs wich i dont see as files and scan didnt help me to find them. Using google search i found that Synology has own system to populate space for virtual mashines. I am wondering, do someone know how to get access the data in order to restore everything need to my client? Any advice or software i can use for that?
Thanks in advance.

[Tomset]

Linuх (Ubunta) + mdadm + lvm2

[MasterOfpuppets]

Linuх (Ubunta) + mdadm + lvm2

How does it help? I don’t have problem accessing file system, and it is not lvm2 configured. There is some synology metadata has been used to operate with VMs

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[data-medics]

Looks like those may be disk images in that folder. I'm assuming they were using it as a iSCSI target for the VM's? Most likely it's just thin provisioning and you'll need to stitch some of those files together to get a complete image.

[MasterOfpuppets]

Looks like those may be disk images in that folder. I'm assuming they were using it as a iSCSI target for the VM's? Most likely it's just thin provisioning and you'll need to stitch some of those files together to get a complete image.

Thanks for advice. Yeah, i've thought so and researched those EP files. What i found , there is NTFS structures like in a regular VM files but data distributed with 4K cluster size across all of them with unknown for me mechanism. And it is not RAID type sheme nor JBOD All of them contain some unique header block at the beginning.

[Dmitri]

Yes, this was an iSCSI target and you need to handle those files as images.

And you'll need to assemble the ones with the numbers manually.

Should you find yourself stuck with that, please feel free to contact me, we can help with this NAS remotely.

[colanco]

Due of hardware issue 2 disks failed and completely unrecoverable.

What hardware problem caused two disks to be unrecoverable?

[Onzmill]

Have you tried Reclaime Pro software? I have seen there option to work with Synology NAS .

[fzabkar]

Due of hardware issue 2 disks failed and completely unrecoverable.

What hardware problem caused two disks to be unrecoverable?

That was my thought as well. It would be a shame if the OP were going to all this trouble over a couple of shorted TVS diodes, for example.

[MasterOfpuppets]

Have you tried Reclaime Pro software? I have seen there option to work with Synology NAS .

It is not capable even to work out any raid6 with two failed disks. There is no such option to skipe 2 drives same time

[MasterOfpuppets]

Due of hardware issue 2 disks failed and completely unrecoverable.

What hardware problem caused two disks to be unrecoverable?

That was my thought as well. It would be a shame if the OP were going to all this trouble over a couple of shorted TVS diodes, for example.

Of cource we tested both failed drives. One of them had failed long ago another disk has media damaged (scratches). They are Seagates. Synology is not running without two disks, due of some reasons

[mr_spokk]

Pretty much game over...Raid6 does not work with 2 drives missing...due to the algorithm for Raid6.
But if you can access the file system with 2 drives missing and get some good files, it's not a Raid6 configuration...maby a jbod?

[DR-Kiev]

Based on my experience to deal with many Synology Nas, you have two options.
1) Use R-studio to create same Raid6 without 2 disks.

In such an occasion very useful option to make reverse raid from the one you have just created. Make images of those two skipped drives.
Than, find log files and find identifiers of two failed disks and write them to proper place in meta data sections to a new clones.
Put all drives back to Synology enclosure and try to run it.

2) About Synology unique system.
In a separate folder, there is should be big file (many Gb size) with a translation table. Where mentioned identifiers in a header and layout of clusters distributing across EP... files.
Try to decode that table in order to create VM based on EP_Dat files.
It is a bit complex work, i have done that before successfully. Feels free to contact me, i can try to help remotely.
Since, you cant recieve/send PM messages. Contact me via skype: vladimirgintov or via whatsApp +971552737521
Cheers.

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reversRaid.jpg (31.76 KiB) Viewed 9519 times

[MasterOfpuppets]

1) Use R-studio to create same Raid6 without 2 disks.

In such an occasion very useful option to make reverse raid from the one you have just created. Make images of those two skipped drives.
Than, find log files and find identifiers of two failed disks and write them to proper place in meta data sections to a new clones.
Put all drives back to Synology enclosure and try to run it.

Wow, thanks for advice. I never used that option before. Time to try.

[MasterOfpuppets]

Pretty much game over...Raid6 does not work with 2 drives missing...due to the algorithm for Raid6.
But if you can access the file system with 2 drives missing and get some good files, it's not a Raid6 configuration...maby a jbod?

For me, Raid6, missing two drives construction usually worked with Recovery Explorer Professional. Reclaime Pro - not, thats true.

[fzabkar]

https://en.wikipedia.org/wiki/RAID_6

According to the Storage Networking Industry Association (SNIA), the definition of RAID 6 is: "Any form of RAID that can continue to execute read and write requests to all of a RAID array's virtual disks in the presence of any two concurrent disk failures. Several methods, including dual check data computations (parity and Reed-Solomon), orthogonal dual parity check data and diagonal parity, have been used to implement RAID Level 6."

[MasterOfpuppets]

Case solved
Thanks to Vladimir (Dr-Kiev) for remote support. I never expected such a difficult work with this NAS

[northwind]

As always, nice job, Vova.