Ultra 4 originally with 3 2TB drives (from compatibility list). Drive 3 reported dead, so I replaced it with a 3TB drive (from compatibility list). The intent was to add another matching 3TB dive to bay 4 after the sync, so I currently have that as a spare.
I get the following error messages: Popup Window: RAID sync finished on volume C. The array is still in degraded mode, however. This can be caused by a disk sync failure or failed disks in a multi-parity disk array. Popup Window: Detected increasing ATA errors on disk 2[ST32000542AS, 6XW1P8BM] 39 times in the past 30 days. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy. Frontview Shares Tab: On life support - access to volume disabled. To restore volume, shutdown this device, reconnect the disk(s) if they had been inadvertently disconnected, and power the device back on. To avoid permanently rendering the disk unusable, do not reconnect the disk(s) while the power is on. Frontview Health Tab: Shows drive 2 dead, whereas it was previously reported healthy.
Since I've already tried to power down, pull out and re-insert the drives, power back up only to get the same messages, I'm confused on what to try next. The shares are inaccessible, so I have been unable to copy the files to safety.
Could one of the experts please give advice on what I should do? Thanks.
I googled and found quite a few forum posts and sites stating the ReadyNAS falsely was falsely reporting good drives as bad.
Not the ST32000542AS.
ATA errors include garbled commands that the drive correctly rejects - so backplane issues or even firmware bugs can provoke them. Of course a failing drive is also a cause. But if Seatools passes, and if you are still under warranty for the ultra (3 years for the original purchaser) you might contact Netgear support.
Also, I've found that the write test (seatools advanced tests) does find issues that the non-destructive tests miss. So you could try that as well (though it still will wipe the drives).
Even if the tests don't pick up anything, I would still be concerned. If disk I/O isn't solid than RAID won't prevent data corruption (though it likely will detect it). If you stick with these drives, I'd be schedule scrubs and file system checks, and keep a close watch for problems.
StephenB Thanks for the advice. I will definitely follow it. The unit is no longer under warranty. Sounds like it's not a good idea to use drives with any hint of problems in RAID. I have decided to not re-install the original drives that were reported bad by the ReadyNAS. When I need more capacity, I will just buy new drives. I'll do the advanced tests on the original drives then re-purpose the passing drives to some other use in such as backup to USB enclosure of non-changing files, used only for recovery.
