RE: RAID halting

["Lelsie Rhorer" <lrhorer@satx.rr.com>]

> > Also, it doesn't take a drive 40 seconds,
> > let alone 2 minutes, to mark a sector bad.
> 
> Just for info, with Enterprise class sata drives, you're right.

On this system, with consumer class drives, with the faulty RAID enclosure,
the system marked well over a million sectors bad.  Except when the entire
drive was faulted and taken offline, it never caused a halt of this
magnitude, and every single block of sectors marked bad was reported in the
kernel log.  I can't guarantee this is not what is happening, but I am
highly skeptical, to say the least.  You're also going to have to explain to
me why 5 drives stop reading and 5 do not, and why it is always the same 5
drives.  One flaky drive I can believe.  Five I can't.  You're also going to
have to explain to me why there are no reports of sectors marked bad in the
kernel log when these events occur, although at long intervals (months),
occasionally a block of bad sectors will be reported.

> For consumer grade sata, they have extended auto retry logic as an
> effort not to fail a read from a bad sector.  It can easily take times
> like your seeing.  I think the standard drive timeout is on the order
> of 30 seconds and then libata sometimes has retry logic of its own.
I have never seen any of the marked failures take that long.  As I said,
there were well over a million marked bad, usually in chunks of 128 sectors.

> Especially with PATA drives a 2 minute issue is not out of the
> question, since the kernel will step down the i/o speed and retry each
> speed as it goes.  And PATA (IDE) has a lot of speeds to try.

In my original message I already said these are 1T SATA drives spread across
three different port multipliers.

--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html