I have ZFS With raidz1, 6 x ST3000DM001 3 is PN:9YN166 and 3 is PN:1CH166.

First 1 PN:9YN166 drive failed and was offline to the NAS, i rebooted and it was back online. Then it failed again, then i understand something was really wrong. I rebooted once more With logging options. Lots of error Message like DRDY, error 51 or something. and retires, giving up after number og mili Seconds.

After 1 more reboot the drive was not detectable by bios, it's sounds normal.
I replace drive, startet rebuild, then the second PN:9YN166 drive failed. After a reboot the same error Messages like the other one. Then i tried Victoria and it said Drive not say DRSC, DRDY or not remove BUSY cannot working for both drives.

I rebooted and it was still rebuilding with extrem error rate. after a while the Third and last PN:9YN166 drive failed.

There has to be some know problems with the PN:9YN166 product line, i asked Seagate support With no Luck.

There is normal sounds, while it was booting and retrying and failing it made a repeating moving header noise, but normal sounds.

Anyone have a clue what part is most likely malfunction?

First off...I should like to make the suggestion that you never replace and rebuild a failed drive in a RAID array until you make 100% sure that all the data is backed up. When a rebuild starts, it goes through every sector of every drive and one bad sector and "boom!" you are down for the count.

In this case, I think you had better stop and get a full sector-by-sector clone of all the drives that were active in the system. Then, from here, you will have to virtually rebuild the RAIDZ1 and recover the data to another drive. I suspect that you are going to need some assistance and you would be wise to seek professional assistance sooner than later, before the data is completely unrecoverable.

As I always say, there are 3 reasons why we are unable to recover RAIDs:

1. Price is turned down
2. Physical failure beyond recovery
3. Logical damage caused by previous recovery attempts

It should be noted that only a small percentage of data recovery professionals ever encounter RAIDZ1 failures and they aren't as simple as a typical RAID 5 array to recovery. So, you can expect that this type of recovery will be quite expensive.

My team may be able to assist remotely, for a fee, of course.

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Luke
Recovery Force Data Recovery