Re: ZFS RAIDZ2 and wd uncorrectable data error - why does ZFS not notice the hardware error?

[mlelstv%serpens.de@localhost (Michael van Elst)]

gdt%lexort.com@localhost (Greg Troxel) writes:

>Ah, interesting point.  I find this confusing, because I thought an
>uncorrectable read error would, for disks I've dealt with, cause the
>sector to be marked as permanently failed and pending reallocation.

It is. Doesn't mean that further read attempts aren't honored.


>I also didn't realize that wd(4) would issue aother read when there is a
>failure, but maybe that's in zfs glue code.

ZFS also seems to do a retry by itself, so you have wait the wd retries twice.

On Solaris, ZFS can issue a request with the B_FAILFAST flag to instruct
the driver to not attempt retries on its own.