<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Thanks, Russ -- So the "U to -" change doesn't have an associated dmesg? Or is the "raid5: Disk failure on sdf1, disabling device" what would accompany it? I'm assuming a single hard failure is enough to take a drive/slice out of the array?</div><div><br></div><div>What kernel is this on? My md module apparently outputs "md:"-prefixed messages and the only thing I've ever seen from it is for the periodic "data-check of RAID array". There was definitely nothing from it when there were reports from sd about unrecoverable read errors (and associated message about EIO from blk_update_request).</div><div><br></div><div>Unfortunately, the system is remote and all I have is syslog/journald output (I can't run mdadm or the like).</div><div><br></div><div>Jeff</div><div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Aug 21, 2019 at 3:16 PM R P Herrold <<a href="mailto:herrold@owlriver.com">herrold@owlriver.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><br>
When a drive 'falls out' of the array, the 'U' changes to '-' <br>
or such. I have a 'cron' process which watches for such, and <br>
provides notification<br>
<br>...<br>
<br>
from the 'dmesg' on a recent failure:<br>
<br>
end_request: I/O error, dev sdf, sector 2563365089<br>
sd 0:0:5:0: SCSI error: return code = 0x08000002<br>
sdf: Current: sense key: Medium Error<br>
Add. Sense: Unrecovered read error<br>
<br>
end_request: I/O error, dev sdf, sector 2563365033<br>
raid5:md0: read error NOT corrected!! (sector 2563365032 on <br>
sdf1).<br>
raid5: Disk failure on sdf1, disabling device. Operation <br>
continuing on 14 devices<br>
raid5:md0: read error not correctable (sector 2563365040 on <br>
sdf1).<br>
raid5:md0: read error not correctable (sector 2563365048 on <br>
sdf1).<br>
<br>
( as you can see the device failed, and was 'disabled' and <br>
dropped out of the array )<br>
<br><br>
</blockquote></div></div></div></div></div>