Re: bdflush and postgres stuck in D state

[Jakob Østergaard]

On Tue, Sep 18, 2001 at 02:08:20PM -0700, David Rees wrote:
> On Tue, Sep 18, 2001 at 10:49:10AM -0700, Andrew Morton wrote:
> > Jakob Østergaard wrote:
> > > 
> > > Sorry for following up on my own post, I have a little extra
> > > information.
> > > 
> > > I started a g++ job to try to force the machine to write out some dirty
> > > buffers before I reboot.   g++ now hangs along with two sync's, bdflush
> > > and the postgres process.
> > > 
> > 
> > Since 2.4.7 several bugs have been fixed in RAID1 which would
> > cause this, including a missing blockdevice unplug and failure
> > to hang onto the supposedly-reserved RAID1 buffer-heads.
> 
> Even kernels as recent as 2.4.9 have this bug.  See this thread for more
> info and a patch which fixes this bug.
> 
> The thread:
> http://marc.theaimsgroup.com/?t=99911655500004&w=2&r=1
> 
> The patch:
> http://marc.theaimsgroup.com/?l=linux-kernel&m=99913223508789&w=2

Thanks a lot !

Somehow I seem not have lost "most" linux-raid mails, dunno why...  I hadn't
seen that thread before, but it was indeed the problem I saw here too.

I didn't lose any data on the 2.4.7 that did this, but it seems the situation
is more severe in 2.4.9, leading potentially to significant data loss.

/me prepares another boot (and a spare 32MB stick) for the raid-1 box

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