[BlueOnyx:21611] Re: Device: /dev/sdb [SAT], 1 Currently unreadable (pending) sectors

[Michael Stauber]

Hi Fred and Jeff,

> Early warning of impending disk failure, would be my guess. 

That would be my guess as well. Please make sure you have good and
recent backups. If you do not, please take a look at this guide, which
explains how you can create a good and easily restoreable backup set
using CMU:

http://www.blueonyx.it/index.php?page=cmu-migrations

If you are not using a dedicated RAID controller but are using
Software-RAID, then you can check the SMART status of your disks this way:

smartctl -a <drive>

To check /dev/sdb you would run this:

smartctl -a /dev/sdb

That should give you a pretty good report about the health state of the
disk. While at it, also check /dev/sda, because if both are of same
make, model and age, then chances are that it's also fast approaching
the end of it's useful life and you sure don't want to have two disks
fail at the same time, as that will trash your data.

With that info in hand you can then get one or two replacement disks.
Replace /dev/sdb first and let the RAID1 repopulate it with all the
data. Once that's done, you can decide if you want to swap out /dev/sda
with a new one right away or wait until it starts exhibiting problems as
well. If the disks is more than 3-4 years old, then it would be better
to replace it rather sooner than later, though.

-- 
With best regards

Michael Stauber