[ovirt-devel] [VDSM] All tests using directio fail on CI

[Evgheni Dereveanchin]

Hi Yaniv,

this is a physical server with work directories
created on a zRAM device, here's the patch:
https://gerrit.ovirt.org/#/c/62249/2/site/ovirt_jenkins_slave/templates/prepare-ram-disk.service.erb

I'll still need to read up on this but the only
slave having this class (ovirt-srv08) is now offline 
and should not cause issues. I tested on VM slaves 
and did not see errors from the dd test command you provided.

Please tell me if you see errors on other nodes and I'll
check what's going on but it must be something else than RAM disks.

Regards, 
Evgheni Dereveanchin 

----- Original Message -----
From: "Yaniv Kaul" <ykaul at redhat.com>
To: "Evgheni Dereveanchin" <ederevea at redhat.com>
Cc: "infra" <infra at ovirt.org>, "devel" <devel at ovirt.org>, "Eyal Edri" <eedri at redhat.com>, "Nir Soffer" <nsoffer at redhat.com>
Sent: Thursday, 29 September, 2016 9:32:45 AM
Subject: Re: [ovirt-devel] [VDSM] All tests using directio fail on CI

On Sep 29, 2016 10:28 AM, "Evgheni Dereveanchin" <ederevea at redhat.com>
wrote:
>
> Hi,
>
> Indeed the proposed dd test does not work on zRAM slaves.
> Can we modify the job not to run on nodes with ram_disk label?

Are those zram based or ram based *virtio-blk* disks,  or zram/ram disks
within the VMs?
The former should work. The latter -  no idea.

>
> The node will be offline for now until we agree on what to do.
> An option is to abandon RAM disks completely as we didn't find
> any performance benefits from using them so far.

That's very surprising. On my case it doubles the performance,  at least.
But I assume my storage (single disk) is far slower than yours.
Y.

>
> Regards,
> Evgheni Dereveanchin
>
> ----- Original Message -----
> From: "Eyal Edri" <eedri at redhat.com>
> To: "Nir Soffer" <nsoffer at redhat.com>, "Evgheni Dereveanchin" <
ederevea at redhat.com>
> Cc: "Yaniv Kaul" <ykaul at redhat.com>, "devel" <devel at ovirt.org>, "infra" <
infra at ovirt.org>
> Sent: Thursday, 29 September, 2016 8:08:45 AM
> Subject: Re: [ovirt-devel] [VDSM] All tests using directio fail on CI
>
> Evgheni,
> Can you try switching the current RAM drive with zram?
>
> On Wed, Sep 28, 2016 at 11:43 PM, Nir Soffer <nsoffer at redhat.com> wrote:
>
> > On Wed, Sep 28, 2016 at 11:39 PM, Yaniv Kaul <ykaul at redhat.com> wrote:
> > > On Sep 28, 2016 11:37 PM, "Nir Soffer" <nsoffer at redhat.com> wrote:
> > >>
> > >> On Wed, Sep 28, 2016 at 11:20 PM, Nir Soffer <nsoffer at redhat.com>
> > wrote:
> > >> > On Wed, Sep 28, 2016 at 10:31 PM, Barak Korren <bkorren at redhat.com>
> > >> > wrote:
> > >> >> The CI setup did not change recently.
> > >> >
> > >> > Great
> > >> >
> > >> >> All standard-CI jobs run inside mock (chroot) which is stored on
top
> > >> >> of a regular FS, so they should not be affected by the slave OS at
> > all
> > >> >> as far as FS settings go.
> > >> >>
> > >> >> But perhaps some slave-OS/mock-OS combination is acting
strangely, so
> > >> >> could you be more specific and point to particular job runs that
> > fail?
> > >> >
> > >> > This jobs failed, but it was deleted (I get 404 now):
> > >> > http://jenkins.ovirt.org/job/vdsm_master_check-patch-fc24-
> > x86_64/2530/
> > >>
> > >> Oops, wrong build.
> > >>
> > >> This is the failing build:
> > >>
> > >>
> > >> http://jenkins.ovirt.org/job/vdsm_master_check-patch-el7-
> > x86_64/1054/console
> > >>
> > >> And this is probably the reason - using a ram disk:
> > >>
> > >> 12:24:53 Building remotely on ovirt-srv08.phx.ovirt.org (phx physical
> > >> integ-tests ram_disk fc23) in workspace
> > >> /home/jenkins/workspace/vdsm_master_check-patch-el7-x86_64
> > >>
> > >> We cannot run the storage tests using a ramdisk. We are creating
> > >> (tiny) volumes and storage domains and doing copies, this code cannot
> > >> work with ramdisk.
> > >
> > > Will it work on zram?
> > > What if we configure ram based iSCSI targets?
> >
> > I don't know, but it is easy to test - it this works the tests will
work:
> >
> > dd if=/dev/zero of=file bs=512 count=1 oflag=direct
> > _______________________________________________
> > Infra mailing list
> > Infra at ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/infra
> >
> >
> >
>
>
> --
> Eyal Edri
> Associate Manager
> RHV DevOps
> EMEA ENG Virtualization R&D
> Red Hat Israel
>
> phone: +972-9-7692018
> irc: eedri (on #tlv #rhev-dev #rhev-integ)