Re: nonzero mismatch_cnt with no earlier error

[Jason Rainforest <l3mming@iinet.net.au>]

I tried doing a check, found a mismatch_cnt of 8 (7*250Gb SW RAID5,
multiple controllers on Linux 2.6.19.2, SMP x86-64 on Athlon64 X2 4200
+).

I then ordered a resync. The mismatch_cnt returned to 0 at the start of
the resync, but around the same time that it went up to 8 with the
check, it went up to 8 in the resync. After the resync, it still is 8. I
haven't ordered a check since the resync completed.


On Sat, 2007-02-24 at 04:37 -0500, Justin Piszcz wrote:
> Of course you could just run repair but then you would never know that 
> mismatch_cnt was > 0.
> 
> Justin.
> 
> On Sat, 24 Feb 2007, Justin Piszcz wrote:
> 
> > Perhaps,
> >
> > The way it works (I believe is as follows)
> >
> > 1. echo check > sync_action
> > 2. If mismatch_cnt > 0 then run:
> > 3. echo repair > sync_action
> > 4. Re-run #1
> > 5. Check to make sure it is back to 0.
> >
> > Justin.
> >
> > On Sat, 24 Feb 2007, Eyal Lebedinsky wrote:
> >
> >> I did a resync since, which ended up with the same mismatch_cnt of 184.
> >> I noticed that the count *was* reset to zero when the resync started,
> >> but ended up with 184 (same as after the check).
> >> 
> >> I thought that the resync just calculates fresh parity and does not
> >> bother checking if it is different. So what does this final count mean?
> >> 
> >> This leads me to ask: why bother doing a check if I will always run
> >> a resync after an error - better run a resync in the first place?
> >> 
> >> -- 
> >> Eyal Lebedinsky (eyal@eyal.emu.id.au) <http://samba.org/eyal/>
> >> 	attach .zip as .dat
> >> -
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> >> 
> >
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