Libguestfs - Feb 2018 - Re: [ovirt-users] Slow conversion from VMware in 4.1

On Thu, Jan 25, 2018 at 10:53:28AM +0100, Luca 'remix_tj' Lorenzetto
wrote:
> On Thu, Jan 25, 2018 at 10:08 AM, Richard W.M. Jones
<rjones@redhat.com> wrote:
> > There's got to be some difference between your staging environment
and
> > your production environment, and I'm pretty sure it has nothing to
do
> > with the version of oVirt.
> >
> > Are you running virt-v2v inside a virtual machine, and previously you
> > ran it on bare-metal?  Or did you disable nested KVM?  That seems like
> > the most likely explanation for the difference (although I'm
surprised
> > that the difference is so large).
> >
> > Rich.
> >
> 
> Hello Rich,
> 
> i'm running virt-v2v throught the import option of oVirt.
Unfortunately the ‘-i vmx’ method is not yet supported when using the
oVirt UI.  However it will work from the command line[0] if you just
upgrade virt-v2v using the RHEL 7.5 preview repo I linked to before.

‘-i vmx’ will be by far the fastest way to transfer guests available
currently, (unless you want to get into VDDK which currently requires
a lot of fiddly setup[1]).
> [root@kvm01 ~]# rpm -qa virt-v2v
> virt-v2v-1.36.3-6.el7_4.3.x86_64
> [root@kvm01 ~]# rpm -qa libguestfs
> libguestfs-1.36.3-6.el7_4.3.x86_64
> [root@kvm01 ~]# rpm -qa
"redhat-virtualization-host-image-update*"
> redhat-virtualization-host-image-update-placeholder-4.1-8.1.el7.noarch
> redhat-virtualization-host-image-update-4.1-20171207.0.el7_4.noarch
> 
> (yes, i'm running RHV, but i think this shouldn't change the
behaviour)
> 
> I don't set anything in the commandline or whatever, i set only the
> source and destination throught the API. So virt-v2v is coordinated
> via vdsm and runs on the bare-metal host.
> 
> The network distance is "0", because vcenter, source vmware
hosts, kvm
> hosts and ovirt hosts lies in the same network. The only annotation is
> that also vCenter is a VM, running on esx environment.
> 
> Network interfaces both on source and destination are 10Gbit, but
> there may be a little slowdown on vcenter side because has to get the
> data from esx's datastore and forward to the ovirt host.
I don't know why it slowed down, but I'm pretty sure it's got
nothing
to do with the version of oVirt/RHV.  Especially in the initial phase
where it's virt-v2v reading the guest from vCenter.  Something must
have changed or be different in the test and production environments.

Are you converting the same guests?  virt-v2v is data-driven, so
different guests require different operations, and those can take
different amount of time to run.

Rich.

[0] http://libguestfs.org/virt-v2v.1.html#input-from-vmware-vmx
[1] http://libguestfs.org/virt-v2v.1.html#input-from-vddk

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

Hello Richard,

unfortunately upgrading virt-v2v is not an option. Would be nice, but
integration with vdsm is not yet ready for that options.

On Thu, Jan 25, 2018 at 11:06 AM, Richard W.M. Jones <rjones@redhat.com>
wrote:
[cut]
> I don't know why it slowed down, but I'm pretty sure it's got
nothing
> to do with the version of oVirt/RHV.  Especially in the initial phase
> where it's virt-v2v reading the guest from vCenter.  Something must
> have changed or be different in the test and production environments.
>
> Are you converting the same guests?  virt-v2v is data-driven, so
> different guests require different operations, and those can take
> different amount of time to run.
>
I'm not migrating the same guests, i'm migrating different guest, but
most of them share the same os baseline.
Most of these vms are from the same RHEL 7 template and have little
data difference (few gigs).

Do you know which is the performance impact on vcenter? I'd like to
tune as best as possible the vcenter to improve the migration time.

We have to migrate ~300 guests, and our maintenance window is very
short. We don't want continue the migration for months.

Luca

-- 
"E' assurdo impiegare gli uomini di intelligenza eccellente per fare
calcoli che potrebbero essere affidati a chiunque se si usassero delle
macchine"
Gottfried Wilhelm von Leibnitz, Filosofo e Matematico (1646-1716)

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Ma il problema è che i libri sono tutti sparsi sul pavimento"
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Luca 'remix_tj' Lorenzetto, http://www.remixtj.net ,
<lorenzetto.luca@gmail.com>

On Fri, Feb 02, 2018 at 12:20:14PM +0100, Luca 'remix_tj' Lorenzetto
wrote:
> Hello Richard,
> 
> unfortunately upgrading virt-v2v is not an option. Would be nice, but
> integration with vdsm is not yet ready for that options.
> 
> On Thu, Jan 25, 2018 at 11:06 AM, Richard W.M. Jones
<rjones@redhat.com> wrote:
> [cut]
> > I don't know why it slowed down, but I'm pretty sure it's
got nothing
> > to do with the version of oVirt/RHV.  Especially in the initial phase
> > where it's virt-v2v reading the guest from vCenter.  Something
must
> > have changed or be different in the test and production environments.
> >
> 
> > Are you converting the same guests?  virt-v2v is data-driven, so
> > different guests require different operations, and those can take
> > different amount of time to run.
> >
> 
> I'm not migrating the same guests, i'm migrating different guest,
but
> most of them share the same os baseline.
> Most of these vms are from the same RHEL 7 template and have little
> data difference (few gigs).
> 
> Do you know which is the performance impact on vcenter? I'd like to
> tune as best as possible the vcenter to improve the migration time.
There is a section about this in the virt-v2v man page.  I'm on
a train at the moment but you should be able to find it.  Try to
run many conversions, at least 4 or 8 would be good places to start.
> We have to migrate ~300 guests, and our maintenance window is very
> short. We don't want continue the migration for months.
SSH or VDDK method would be far faster but if you can't upgrade
you're stuck with https to vCenter.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v