Working on an Iomega StorCenter 150d NAS. It has 4 250GB drives. System became unresponsive after power failure and cannot be detected on network. SMART status on individual drives is OK and they have no bad sectors. Drives have been imaged and when the array is reconstructed virtually (RAID5, left symmetric, 4kb stripe, parity delay 1) the file system is detected and shares can be mounted and data recovered however many (but not all) of the files are corrupted. I've tried a few permutations of the parity distribution but this leads to an unmountable FS. I'm trying to determine whether this corruption is caused by incorrect configuration during the virtual rebuild or whether the data has actually been corrupted either by a failure of the Silicon Image SATALink Sil3114CTU controller or possibly bad RAM (it has 256MB of PC3200) causing it to write garbage data.

Thoughts?

1) Has long has the NAS been running for?
2) What is MDL of the original drives?
3) Have you verified SMART status with more than one SMART utility?

_________________
Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

According to my notes, your virtual construction is fine, only one thing : didn't you forget to set offset 8225280 ?

In your place i would try to unselect drives in construction one by one to exclude the drive which happend to be not working for some period of time.

_________________
Angel Data Recovery

Re: labtech
Drives are Seagate Barracude 7200.10 ST3250620AS. SMART status of drives shows a runtime of almost 40,000 hours. Yes, SMART status was checked with multiple utilities and all drives are healthy with no flagged attributes or errors in the log. Imaging for all drives completed without any read errors so I can verify that the drives are completely free of bad sectors.

Re: Dr-Kiev
I did indeed set offset to 8225280, just forgot to mention in my summary. I'm trying what you suggested regarding taking one drive out of the rebuild and it has some interesting results so far: rebuild without drive #4 results in a somewhat different directory structure with several folders not present that were there in the full 4 drive rebuild. Still there are corrupt files. I will retry alternating the offline drive.

Any thoughts on the significance of this?

If none of the drives are stale preventing from building corruption free, then I sort of run out of ideas.

Best regards

_________________
Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

Thank you Dr Kiev! You pointed me in the right direction. Drive 1 appears to have been taken offline and was corrupting the rebuild. I'm verifying results now but it looks very promising.