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

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

On Fri, Feb 2, 2018 at 12:52 PM, Richard W.M. Jones <rjones@redhat.com>
wrote:
> 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.
Hello Richard,

read the man but found nothing explicit about resource usage. Anyway,
digging on our setup i found out that vcenter when on low cpu usage is
95%.
I think our windows admins should take care of this.

Luca

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Luca 'remix_tj' Lorenzetto, http://www.remixtj.net ,
<lorenzetto.luca@gmail.com>

On Mon, Feb 05, 2018 at 10:57:58PM +0100, Luca 'remix_tj' Lorenzetto
wrote:
> On Fri, Feb 2, 2018 at 12:52 PM, Richard W.M. Jones
<rjones@redhat.com> wrote:
> > 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.
> 
> Hello Richard,
> 
> read the man but found nothing explicit about resource usage. Anyway,
> digging on our setup i found out that vcenter when on low cpu usage is
> 95%.
> I think our windows admins should take care of this.
http://libguestfs.org/virt-v2v.1.html#vmware-vcenter-resources

You should be able to run multiple conversions in parallel
to improve throughput.

The only long-term solution is to use a different method such as VMX
over SSH.  vCenter is just fundamentally bad.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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