[Gluster-users] back to problems: gluster 3.5.4, qemu and debian 8

Tue Aug 4 13:06:50 UTC 2015

Hi all,
I'm back and tested those things.
Michael was right. I've enabled read-ahead option and nothing changed.
So the thing causes the problem with libgfapi and d8 virtio drivers
is performance.write-behind. If it is off, everything works perfect. If I
set it On, different problems are as result (which were confirmed by other
user with same configuration).

2015-07-20 1:53 GMT+03:00 Roman <romeo.r at gmail.com>:

> Thanks for your reply.
> I will test these options as soon as I'm back from ma vacation (2 weeks
> from now on). I'll be too far from servers to change something even on
> testing volume 8)
>
> 2015-07-19 23:47 GMT+03:00 Niels de Vos <ndevos at redhat.com>:
>
>> On Sat, Jul 18, 2015 at 03:56:37PM +0000, Michael Mol wrote:
>> > I think you'll find it's the write-behind that was killing you.
>> > Write-behind opens you up to a number of data consistency issues, and I
>> > strongly disrecommend it unless you have a rock-solid infrastructure
>> from
>> > the writer all the way to the disk the data ultimately sits on.
>>
>> The suggestion to disable these two options was to change the access
>> pattern done by Qemu+libgfapi. Without looking into the source code, I
>> do not know how write-behind and read-ahead play together. Anything that
>> is "written behind" should get flushed when a "read ahead" operation
>> overlaps a "written behind" area. There have been issues with
>> write-behind before, where the flushing was not done in some corner
>> case (https://github.com/gluster/glusterfs/commit/b0515e2a). Maybe this
>> is something similar.
>>
>> > I bet that if you re-enabled read-ahead, you won't see the problem. Just
>> > leave write-behind off.
>>
>> Indeed, write-behind is most likely. Both results of one of the options
>> disabled at the time would be interesting to have.
>>
>> Once it is clear which option causes the problem, we can analyze the
>> access pattern and hopefully fix the xlator.
>>
>> Thanks,
>> Niels
>>
>>
>> > On Sat, Jul 18, 2015, 10:44 AM Roman <romeo.r at gmail.com> wrote:
>> >
>> > solved after I've added (thanks to Niels de Vos) these options to the
>> > volumes:
>> >
>> > performance.read-ahead: off
>> >
>> > performance.write-behind: off
>> >
>> >
>> > 2015-07-15 17:23 GMT+03:00 Roman <romeo.r at gmail.com>:
>> >
>> > hey,
>> >
>> > I've updated the bug, if some1 has some ideas - share plz.
>> >
>> > https://bugzilla.redhat.com/show_bug.cgi?id=1242913
>> >
>> >
>> > 2015-07-14 19:14 GMT+03:00 Kaushal M <kshlmster at gmail.com>:
>> >
>> >  Just a wild guess. What is the filesystem used for the debian 8
>> > installation? It could be the culprit.
>> >
>> > On Tue, Jul 14, 2015 at 7:27 PM, Roman <romeo.r at gmail.com> wrote:
>> > > I've done this way: installed debian8 on local disks using netinstall
>> iso,
>> > > created a template of it and then cloned (full clone) it to glusterfs
>> > > storage backend. VM boots and runs fine... untill I start to install
>> > > something massive (DE ie). Last time it was mate failed to install
>> due to
>> > > python-gtk2 package problems (complaing that it could not compile it)
>> > >
>> >
>> > > 2015-07-14 16:37 GMT+03:00 Scott Harvanek <scott.harvanek at login.com>:
>> > >>
>> > >> What happens if you install from a full CD and not a net-install?
>> > >>
>> > >> Limit the variables.  Currently you are relying on remote mirrors and
>> > >> Internet connectivity.
>> > >>
>> > >> It's either a Proxmox or Debian issue, I really don't think it's
>> Gluster.
>> > >> We have hundreds of Jessie installs running on GlusterFS backends.
>> > >>
>> > >> --
>> > >> Scott H.
>> > >> Login, LLC.
>> > >>
>> > >>
>> > >>
>> > >> Roman
>> > >> July 14, 2015 at 9:30 AM
>> > >> Hey,
>> > >>
>> > >> thanks for reply.
>> > >> If it would be networking related, it would affect everything. But
>> it is
>> > >> only debian 8 which won't install.
>> > >> And yes, i did iperf test between gluster and proxmox nodes. Its ok.
>> > >> Installation fails on every node, where i try to install d8.
>> Sometimes it
>> > >> goes well (today 1 of 6 tries was fine). Other distros install fine.
>> > >> Sometimes installation process finishes, but VM won't start, just
>> hangs
>> > >> with errors like in this attached.
>> > >>
>> > >>
>> > >>
>> > >>
>> > >> --
>> > >> Best regards,
>> > >> Roman.
>> > >> Scott Harvanek
>> > >> July 14, 2015 at 9:17 AM
>> > >> We don't have this issue, I'll take a stab tho-
>> > >>
>> > >> Have you confirmed everything is good on the network side of things?
>> > >> MTU/Loss/Errors?
>> > >>
>> > >> Is your inconsistency linked to one specific brick? Have you tried
>> > running
>> > >> a replica instead of distributed?
>> > >>
>> > >>
>> > >>
>> > >> _______________________________________________
>> > >> Gluster-users mailing list
>> >
>> > >> Gluster-users at gluster.org
>> > >> http://www.gluster.org/mailman/listinfo/gluster-users
>> > >> Roman
>> > >> July 14, 2015 at 6:38 AM
>> > >> here is one of the errors example. its like files that debian
>> installer
>> > >> copies to the virtual disk that is located on glusterfs storage are
>> > getting
>> > >> corrupted.
>> > >> in-target is /dev/vda1
>> > >>
>> > >>
>> > >>
>> > >>
>> > >>
>> > >> --
>> > >> Best regards,
>> > >> Roman.
>> > >> _______________________________________________
>> > >> Gluster-users mailing list
>> > >> Gluster-users at gluster.org
>> > >> http://www.gluster.org/mailman/listinfo/gluster-users
>> > >> Roman
>> > >> July 14, 2015 at 4:50 AM
>> > >> Ubuntu 14.04 LTS base install and then mate install were fine!
>> > >>
>> > >>
>> > >>
>> > >>
>> > >> --
>> > >> Best regards,
>> > >> Roman.
>> > >> _______________________________________________
>> > >> Gluster-users mailing list
>> > >> Gluster-users at gluster.org
>> > >> http://www.gluster.org/mailman/listinfo/gluster-users
>> > >> Roman
>> > >> July 13, 2015 at 7:35 PM
>> > >> Bah... the randomness of this issue is killing me.
>> > >> Not only HA volumes are affected. Got an error during installation
>> of d8
>> > >> with mate (on python-gtk2 pkg) on Distributed volume also.
>> > >> I've checked the MD5SUM of installation iso, its ok.
>> > >>
>> > >> Shortly after that on the same VE node I installed D7 with Gnome
>> without
>> > >> any problem on the HA glusterf volume.
>> > >>
>> > >> And on the same VE node I've installed D8 with both Mate and Gnome
>> using
>> > >> local storage disks without problems. There is a bug somewhere in
>> > gluster or
>> > >> qemu... Proxmox uses RH kernel btw:
>> > >>
>> > >> Linux services 2.6.32-37-pve
>> > >> QEMU emulator version 2.2.1
>> > >> glusterfs 3.6.4
>> > >>
>> > >> any ideas?
>> > >> I'm ready to help to investigate this bug.
>> > >> When sun will shine, I'll try to install latest Ubuntu also. But now
>> I'm
>> > >> going to sleep.
>> > >>
>> > >>
>> > >>
>> > >>
>> > >> --
>> > >> Best regards,
>> > >> Roman.
>> > >> _______________________________________________
>> > >> Gluster-users mailing list
>> > >> Gluster-users at gluster.org
>> > >> http://www.gluster.org/mailman/listinfo/gluster-users
>> > >>
>> > >>
>> > >
>> > >
>> > >
>> > > --
>> > > Best regards,
>> > > Roman.
>> > >
>> > > _______________________________________________
>> > > Gluster-users mailing list
>> > > Gluster-users at gluster.org
>> > > http://www.gluster.org/mailman/listinfo/gluster-users
>> >
>> >
>> >
>> > --
>> >
>> > Best regards,
>> > Roman.
>> >
>> >
>> >
>> > --
>> >
>> > Best regards,
>> > Roman.
>> >
>> > _______________________________________________
>> > Gluster-users mailing list
>> > Gluster-users at gluster.org
>> > http://www.gluster.org/mailman/listinfo/gluster-users
>>
>> > _______________________________________________
>> > Gluster-users mailing list
>> > Gluster-users at gluster.org
>> > http://www.gluster.org/mailman/listinfo/gluster-users
>>
>>
>
>
> --
> Best regards,
> Roman.
>

-- 
Best regards,
Roman.
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