On Mon 02 Mar 2015 04:22:00 PM Mikael Abrahamsson wrote:

On Mon, 2 Mar 2015, Wilson, Jonathan wrote:

quoted

While the monthly scrub was running the following errors (at the bottom
of the post, copied from syslog) were issued.

As soon as you get UNC, it's the drive reporting that it can't
successfully read a sector. Usually this sector is then reported as
"pending" in your SMART output.

Since the log you provided shows a lot of sectors being corrected and you
after that have 0 pending sectors on the drive, I'd say you are now fine.
I would run a new scrub manually in a few days just to check, but you
might be fine going forward. There is no really good way to know, but
generally, a drive that throws a bunch of UNC should be monitored so this
isn't becoming a common problem. I tend to replace drives that have thrown
these kinds of errors if it happens on any kind of regular basis.

Dumb question, but after pending, I assume they go into the reallocated 
column? I think after a certain number of those, you should start thinking 
about a replacement. Like with my recent issues, I had two drives with a few 
too many reallocated sectors. One was over 16k and the other was over 32k. 
They still "work", but I replaced them with WD Reds anyhow. Another drive 
seemed to max out the start-stop count field at 65536. Hah. No more cheap 
desktop seagates in raid for this fellow.

-- 
Thomas Fjellstrom
thomas@fjellstrom.ca