Re: Repeatable, raid1+O_DIRECT, hang/warn

["Dr. David Alan Gilbert" <linux@treblig.org>]

* Zdenek Kabelac (zkabelac@redhat.com) wrote:
> Dne 14. 06. 26 v 19:57 Dr. David Alan Gilbert napsal(a):
> > Hi,
> >    I've got a repeatable raid hang/warn and would appreciate some pointers
> > as where to debug.
> >    (I've been logging stuff on  https://bugzilla.kernel.org/show_bug.cgi?id=221535 )
> > 
> >    This started off as debugging a case where I'd get my RAID1 (on the host)
> > getting a reliable 'rescheduling sector'/disk failure while running the qemu block test suite
> > during a qemu build, but then I tried to build a smaller discrete
> > test, and now I've got a simply triggerable warn and test hang.
> > There's no errors from the underlying SATA layer on the storage,
> > everything resyncs just fine.
> > 
> > I've got an existing LVM vg ('main') with two mirrors on sda2, and sdb2
> > which are SATA disks.
> > 
> > # lvcreate --type mirror --mirrors 1 -L 1G main /dev/sda2 /dev/sdb2
> > 
> 
> Hi
> 
> It's probably worth to say here - the '--type mirror' is the OLD
> (historical) DM mirror target implementation - this target is now in the not
> so active development as users are supposed to be using newer (and faster)
> md wrapped '--type raid1'

Ah, that might have been when I split off to using a separate test
LV rather than risking my LV containing actual useful data and had to
try and find the lvcreate command.

> So if you use   'lvcreate -m1 ....'   you get 'auto-magically' this
> mirroring target.

Thanks,

Dave

> But this obviously doesn't fix the problem if old mirror target...
> 
> Regards
> 
> Zdenek
> 
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