Re: [Qemu-block] [ovirt-users] Re: Debugging ceph access

[Bernhard Dick]

Hi,

Am 05.06.2018 um 22:11 schrieb Nir Soffer:
> On Fri, Jun 1, 2018 at 3:54 PM Stefan Hajnoczi <address@hidden 
> <mailto:address@hidden>> wrote:
>
>     On Thu, May 31, 2018 at 11:02:01PM +0300, Nir Soffer wrote:
>      > On Thu, May 31, 2018 at 1:55 AM Bernhard Dick <address@hidden
>     <mailto:address@hidden>> wrote:
>      >
>      > > Hi,
>      > >
>      > > I found the reason for my timeout problems: It is the version
>     of librbd1
>      > > (which is 0.94.5) in conjunction with my CEPH test-environment
>     which is
>      > > running the luminous release.
>      > > When I install the librbd1 (and librados2) packages from the
>      > > centos-ceph-luminous repository (version 12.2.5) I'm able to
>     start and
>      > > migrate VMs inbetween the hosts.
>      > >
>      >
>      > vdsm does not require librbd since qemu brings this dependency,
>     and vdsm
>      > does not access ceph directly yet.
>      >
>      > Maybe qemu should require newer version of librbd?
>
>     Upstream QEMU builds against any librbd version that exports the
>     necessary APIs.
>
>     The choice of library versions is mostly up to distro package
>     maintainers.
>
>     Have you filed a bug against Ceph on the distro you are using?
>
>
> Thanks for clearing this up Stefan.
>
> Bernhard, can you give more info about your Linux version and
> installed packages (.e.g qemu-*)?
Sure. I have two test-systems. The first is running a stock oVirt Node 
4.3 which states "CentOS Linux release 7.5.1804 (Core)" as version 
string. The qemu and ceph packages are:
Name        : qemu-img-ev
Arch        : x86_64
Epoch       : 10
Version     : 2.10.0
Release     : 21.el7_5.3.1

Name        : qemu-kvm-common-ev
Arch        : x86_64
Epoch       : 10
Version     : 2.10.0
Release     : 21.el7_5.3.1

Name        : qemu-kvm-ev
Arch        : x86_64
Epoch       : 10
Version     : 2.10.0
Release     : 21.el7_5.3.1

Name        : librados2
Arch        : x86_64
Epoch       : 1
Version     : 0.94.5
Release     : 2.el7

Name        : librbd1
Arch        : x86_64
Epoch       : 1
Version     : 0.94.5
Release     : 2.el7

The Centos 7 system is a centos minimal installation with the following 
repos being enabled:
CentOS-7 - Base
CentOS-7 - Updates
CentOS-7 - Extras
ovirt-4.2-epel
ovirt-4.2-centos-gluster123
ovirt-4.2-virtio-win-latest
ovirt-4.2-centos-qemu-ev
ovirt-4.2-centos-opstools
centos-sclo-rh-release
ovirt-4.2-centos-ovirt42
ovirt-4.2

The version numbers for the qemu packages are the same as above as 
they're from the ovirt-4.2-centos-qemu-ev repository. Also the version 
numbers for librados2 and librbd1 match, while they're from the 
centos-base (instead of ovirt-base) repository.

When I activate the ceph-centos-luminous repository librbd1 and 
librados2 get upgraded to the following versions (leaving the qemu 
packages untouched, what is as expected):
Name        : librados2
Arch        : x86_64
Epoch       : 2
Version     : 12.2.5
Release     : 0.el7

Name        : librbd1
Arch        : x86_64
Epoch       : 2
Version     : 12.2.5
Release     : 0.el7

So from my perspective on side of oVirt there should be thaught about a 
way to add a more recent ceph library version into the ovirt node image, 
as it is not the most common task to add extra repositories here (and 
I'm not whether that might break the image based upgrade-path).

I will go for Centos based hosts in my case, as I'm a bit more flexible 
than so at least for me there is no real need to get the above noted 
implemented quickly :-)

  Regards
    Bernhard