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[MoltenSwine]

Hi

My DNS-345 has 4 drives in a JBOD array. While trying to fix unrelated minor issues, a factory reset left my volume inaccessible. To my knowledge all data is intact and the drives healthy. I just need to rebuild the volume without formatting.

Can anyone help?

[MoltenSwine]

Tried swapping out 4 other hdds and configuring DNS-345 with a JBOD volume, then swapping the drives back.

No luck.

[ivan]

You do realise that a JBOD set is ONE VOLUME spread out over several disks.  That means if one disk has problems then you are very likely to lose all your data that has been added since your last tested backup.  Swapping disks out and back in and getting them in different slots breaks the JBOD set.

You might be able to recover some of your data but it will cost you.

Read the data recovery sticky at the beginning of this forum, then download the manuals for the two software solutions (an IFS will not see the JBOD set), read them and decide which one to buy and use.

[MoltenSwine]

Of course I realize this. I did not remove the disks and they are not faulty. The DNS-345 config file got broken and I just need to tell it how to read the volume again. I'm terribly disappointed that you can't just set up the Volume without formatting. This is all I need to do. It looks like I will, however, have to find a desktop pc with 4 bays and copy it to a new NAS. Considering the circumstances and the complete lack of support, it is highly unlikely that my new NAS will be a D-Link.

[ivan]

The JBOD configuration is held on the disks.  It was placed there when you formatted them as a JBOD set.

The fact that you have lost the JBOD information points to the fact that one of the disks has had an unrecoverable read error and the disk firmware has flagged that sector as bad and replaced it with one of the reserve sectors.  The only way to recover data in that situation is to use data recovery software and R-Studio appears to be the only one that works with JBOD sets by reading the raw data on the disks and creating a virtual drive of the JBOD set.  Just installing the disks in a computer that can read the Ext3/4 file system will not recover any data since the JBOD set is broken.

[MoltenSwine]

I assure you that nothing has happened to the disks. Everything worked perfectly until I had transfer speed issues. I performed a factory reset to resolve that issue and have been unable to see the JBOD volume since. I just need a way to tell the DNS-345 to assemble those drives as a JBOD volume.

[ivan]

If a disk had a unrecoverable read or write error that caused the disk firmware to mark the sector as bad and bring into use one of the spare sectors you would not know anything about it unless you kept full S.M.A.R.T records of before and after.

Once a JBOD set is broken there is NO WAY of restoring it short of reformatting the set and restoring from backup.  Yes there is software that can analyse each disk and create the JBOD file system as a virtual drive and you can get most of your data back (the exact percentage depends on how much of the disks are readable over the set).

Because a JBOD set is fragile, especially if there are no tested backups available, we always steer our clients away from using it.  It does work but anyone relying on it without making regular backups, especially if the data stored on it is valuable, is being foolish and asking for pain at some time.  Disks fail and it only takes one failure in a JBOD set for you to lose all the data, the same with RAID 0.  Only RAID 1 and 5 give security and continuity should a disk fail.  Backups to another device are the only way to recover from hardware failure.