[CentOS] mdadm raid-check

Mon Nov 16 08:48:37 UTC 2020
hw <hw at gc-24.de>

On Sat, 2020-11-14 at 21:55 -0600, Valeri Galtsev wrote:
> > On Nov 14, 2020, at 8:20 PM, hw <hw at gc-24.de> wrote:
> > 
> > 
> > Hi,
> > 
> > is it required to run /usr/sbin/raid-check once per week?  Centos 7 does
> > this.  Maybe it's sufficient to run it monthly?  IIRC Debian did it monthly.
> On hardware RAIDs I do RAID verification once a week. Once a Month a
> not often enough in my book. That RAID verification effectively
> reads all stripes of all drives (and verifies that content of
> redundant drives is consistent), thus preventing a “time bomb”, when
> a drive left alone for too long, ready to fail in an area which is
> not accessed, and failing when at some point different drive was
> replaced and RAID rebuild has to go over all stripes of all
> drives. Such “multiple failures” are due to poor sysadmin’s work:
> not often enough RAID verification.

You mean there can be failures which can be detected during a
raid-check and can still be repaired using the other disk, but they
can be impossible to repair when a disk has failed?

> If software raid-check does the same, then it makes a lot of sense,
> and I am more with RedHat's weekly cron job, than with Debian’s
> Monthly.

How often do partial failures occur during normal operation?  In case
there was a power failure, it's probably a good idea to do a check

> Valeri
> > I just checked on Fedora 32.  It does not run raid-check at all, at least not
> > via a cron entry.  /usr/sbin/raid-check is available, though.  Is that an
> > oversight?  (I started it manually now and will check if it's run once I update
> > to 33.)