[Users] SIMFS users

[Kir Kolyshkin]

On 07/22/2015 01:21 AM, Pavel Gashev wrote:
> On 22/07/15 00:11, "users-bounces at openvz.org on behalf of Kir Kolyshkin"
> <users-bounces at openvz.org on behalf of kir at openvz.org> wrote:
>> Other "why not simfs" considerations are listed at
>> http://openvz.org/Ploop/Why#Before_ploop
> That¹s good, but there is an issue with using ploops. If you want to
> life-migrate a huge container to another node, it might take hours (or
> even days). Life migration might fail at CPT stage. It¹s not an issue with
> simfs since you can use the --keep-dst option, and continue migration in
> offline mode. Using ploops you have to start migration from the beginning.

No, in fact you don't.

I am not quite sure about Virtuozzo tools, but with my tools (i.e. vzmigrate
from what is now called "legacy OpenVZ") you can use the same "-r no 
--keep-dst"
flags as for simfs, with the very similar effect -- only top delta will 
need to be re-copied
again, for all other deltas rsync will be used just in case of simfs.

Oh, and if the top delta is large, just create a snapshot before trying 
live migration,
or use --snapshot switch to vzmigrate (currently, though, you'll need to 
delete
the snapshot manually after migration -- this is something in my TODO list
I can't find time to implement).

> In other words, a ³showstopper² with ploops is that you can¹t continue
> stopped/failed migrations.

Thanks for detailed explanation, it makes sense, but definitely not for
OpenVZ -- I am pretty sure it works the way I described above.