bad sector in gmirror HDD

[Matthias Andree]

Am 20.08.2011 19:34, schrieb Dan Langille:
> This is an older system.  I suspect insufficient ventilation.  I'll look at getting
> a new case fan, if not some HDD fans.

The answer is quite simple, get new drives.

They have gone for some 24000 hours, IOW, at least 3 years (assuming
24x7), and at around 50 °C, they're worn.  After three years, at the
slightest hitch, replace drives, before Something Bad[tm] happens.
You'll get faster replacements anyhow :)


On a related note, since this is about gmirror:

Linux has a similar subsystem in place called the drive mapper (dm),
with user-space tools mdadm.  The whole rig (kernel + user space)
supports various RAID levels through modules, the gmirror equivalent
being raid1 -- and that module somewhat recently acquired an interesting
*feature:* it can automatically rewrite broken sectors.  Meaning that
when it sees a read error on one drive, it will read the block from the
intact other drive and re-write it on the faulty drive so that it gets
reallocated (assuming nobody turned the drive's ARWE feature off).
Perhaps that's a useful feature for gmirror, too.

> 2848980992 bytes transferred in 127.128503 secs (22410246 bytes/sec)

Eek, someone should fix dd to use proper units and not confuse seconds
(s) with the secans function (sec).

Anyways, that's pretty low by today's standards.  My I/O speeds even on
lowly Samsung 5400/min drives are in excess of 100 MBytes/s, and that's
talking about drives made in 2009.