smartd - Currently unreadable (pending) sectors

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smartd - Currently unreadable (pending) sectors

Raimo Niskanen-7
Hi all.

I just wanted to share a small success story, partly for the archives.

I have an OpenBSD 6.5 amd64 server whose smartd has been whining about:
  smartd[666]: Device: /dev/sd0c, 1 Currently unreadable (pending) sectors

smartctl -a /dev/sd0c showed attribute 197 Current_Pending_Sector to be 1.

The disk is part of a softraid mirror sd2, so I offlined the disk
and rebuilt the mirror, thusly:
  bioctl -O /dev/sd0a sd2
  bioctl -R /dev/sd0a sd2

After a few hours of parity rebuild smartd has stopped spamming
/var/log/messages, and smartctl -a shows Current_Pending_Sector to be 0.
The parity rebuild, as expected, must have re-written the broken sector and
the disk reallocated the sector.

Sysadmin is happy!

Except that smartctl -a informs me that the disk predicts its power-on
lifetime to be 382 days, which apparently is not good.  The other disk
in the mirror says nothing of this, so I have a very early warning
about getting a new disk...  (sd0a's Reallocated_Sector_Ct is 148
while sd0b's is 0)

Best regards
--

/ Raimo Niskanen, Erlang/OTP, Ericsson AB

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Re: smartd - Currently unreadable (pending) sectors

Jan Stary
On Jul 12 08:26:58, [hidden email] wrote:
> Except that smartctl -a informs me that the disk predicts its power-on
> lifetime to be 382 days,

I wouldn't give much weight to such predictions.
See e.g. section 3.5.6 Predictive Power of SMART Parameters
in https://ai.google/research/pubs/pub32774 (usenix 2007).

        Jan