"Block recommended for re-assignment on disk /aggr0/plex0/rg0/0c.27 shelf 1 bay 11 [NETAPP x 279 -......i tried to read the scrub process but did not get anything relating to the above messages. wether my disk is about to fail or ?/
we have FAS 3140 with FC disk DS 14 mk2 ESH4
kinldy suggest some reading to now what exactly going on there
This is a simple "bad block" message. These are pretty common and unless the number reaches a threshold, the disk will not fail. There are many blocks that can be lost without any disruption to data. I would not worry unless you see this occurring multiple times on the same disk.
I have had 10 in one scrub, but across multiple disks. OnTAP is working like it should, I would not be worried.
Honestly, I cannot say...I have seen as many as 10(if I recall correctly) without a disk failing.
I would guess that the algorithm takes disk geometry into account, so that multiple bad blocks in a localized area would be weighted as more serious than the same number, or maybe even more that are spread all over the disk.
There is an option disk.recovery_needed.count that seems to be tied to it, but this option specifically addresses how the filer reacts BEFORE failing the disk.
And according to the NOW site: A disk is put into a recovery-needed state to complete internal sector reassignments.
So I would take that to mean that 5 bad blocks are required for the disk to reassign sectors to avoid those areas, but that is only a guess. The best option might be to open a case with NetApp via the NOW site as a P4, low priority question, and see if they can give more exact information.