AIO, SMB2 and Samba 3.6
Volker.Lendecke at SerNet.DE
Wed Feb 22 04:29:38 MST 2012
On Wed, Feb 22, 2012 at 10:16:14PM +1100, Andrew Bartlett wrote:
> On Wed, 2012-02-22 at 10:54 +0100, Volker Lendecke wrote:
> > On Wed, Feb 22, 2012 at 03:56:52PM +1100, Andrew Bartlett wrote:
> > > I've now reproduced this on the NAS with a level 10 log, using
> > > smbclient4 from master:
> > >
> > > bin/smbclient //192.168.1.167/media -Uuser%password
> > > smb: \> put /data/kvm/cdroms/FreeBSD-8.2-RELEASE-amd64-bootonly.iso
> > > freebsd7.iso
> > > Error writing file: socket_error
> > >
> > > It seems to me that the underlying AIO layer isn't returning promptly or
> > > correctly. It appears that after the socket error, smbclient still
> > > tries to close the file, and this then triggers finally an AIO error.
> > The reference to freebsd makes me wonder if the NAS box
> > might be FreeBSD based.
> Sorry for the red herring. That was just a 50MB file I had lying
> around. It is Linux 184.108.40.206.RNx86_64.2.2 and glibc 2.7-18lenny7.
> > I think I've seen problems with
> > Samba setting up the RT signal we choose for AIO. It should
> > have disabled using aio. Can you check further up in the log
> > whether that might be the case?
> This certainly matches the symptoms: what would the message be in that
> case? The log is the full log from the point of the share connection.
> > Also, you might try the
> > aio_fork and aio_pthread modules.
> Indeed, given the well known performance issues with glibc AIO
> aio_pthread has already been recommended. This task was just to first
> sort out (if possible) why the default aio didn't work at all.
Can you run strace -ttT -o /tmp/smbd.out -f smbd -i
and run the test against that?
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