[Users] New setup - deploy OpenVZ or wait for VZ7?

[Сергей Мамонов]

> Yes, i know it's still possible to create an image which will be
compacted not that efficiently, but this becomes quite a rare case.

But in irl  - get random prodaction node and first container with max delta
(data vs image size) -
ploop-balloon  discard /vz/private/93713/root.hdd/DiskDescriptor.xml --stat
Balloon size:        0MB
Data size:       30845MB
Ploop size:      51200MB
Image size:      47546MB

ploop-balloon  discard /vz/private/93713/root.hdd/DiskDescriptor.xml
--defrag
...

ploop-balloon  discard /vz/private/93713/root.hdd/DiskDescriptor.xml --stat
Balloon size:        0MB
Data size:       30845MB
Ploop size:      51200MB
Image size:      47433MB

And already have 17Gb wasted space for 30Gb data after compact with defrag.
( on node openvz 6  - 2.6.32-042stab114.5 kernel, ploop-1.15-1.x86_64 and
e4defrag2 builded from https://github.com/dmonakhov/e2fsprogs/tree/e4defrag2
with commits from 16 May).

In irl we have significan overhead on disk operations on compact ploop
images.

In irl we regular have ploop images which we cannot umount -
https://bugs.openvz.org/browse/OVZ-6689 !!!

And from time to time backup and compact failed with strange situations
like -  https://bugs.openvz.org/browse/OVZ-6547


2016-06-06 18:13 GMT+03:00 Konstantin Khorenko <khorenko at virtuozzo.com>:

> On 06/06/2016 02:23 PM, Volker Janzen wrote:
>
>> Hi Sergey,
>>
>> On 14:39 Sun 05 Jun , Volker Janzen wrote:
>>>
>>>>
>>>>> Unfortunately no. We don't support upgrade from pre-release version to
>>>>> the final one.
>>>>>
>>>>
>>>> When I use a CentOS 7 as base system and install VZ7 afterward it's not
>>>> possible to upgrade, too?
>>>>
>>>
>>> There is only one supported configuration for new installations -
>>> clean Virtuozzo 7 installation.
>>>
>>
>> okay I see. My setup will be unsupported if installed on plain CentOS 7
>> either way.
>>
>>
>>> It also seems to lack some documentation for my use cases, but I need to
>>>>>> start
>>>>>> with VZ7 sooner or later.
>>>>>>
>>>>>
>>>>> What usecases are you talking about?
>>>>>
>>>>
>>>> My current OpenVZ setup has LVM involved.
>>>> I want to be able to use simfs based storage on an underlaying LVM
>>>> volume.
>>>>
>>>
>>> Why do you prefer simfs instead of ploop? Did you see comparison simfs
>>> vs ploop?
>>> https://openvz.org/CT_storage_backends
>>>
>>
>> I think you asked me about this some time ago. The matrix states:
>> Reliability
>> Low: big amount of files produce ext4 corruption so often
>>
>> Why should I use something that tells me it's not reliable?
>>
>
> Even according to
>
> https://github.com/pavel-odintsov/OpenVZ_ZFS/blob/master/openvz_storage_backends.md
> (which seems to be used as a source of recent page update) this row is
> incorrect, this info has just been added by Narcis Garcia and is to be
> corrected.
>
> i don't want to start a holly war here, i won't tell that ZFS is worse or
> whatever,
> i just know that we really do power crash testing and know the results.
> And i'm certain that our default suggested solution is good and stable.
>
> Yes, there are drawbacks - the most important one now is usage overhead
> (sic!, not stability for a long time already), and we improve it.
> And gained quite a good progress. Just did a ploop compaction of my
> personal work Container, created 03.07.2014 (lot of gits, makes, etc.):
>
> # ploop-balloon discard /vz/private/105/root.hdd/DiskDescriptor.xml
> --defrag
> ...
> # ploop-balloon discard /vz/private/105/root.hdd/DiskDescriptor.xml --stat
> Balloon size:        0MB
> Data size:       29189MB
> Ploop size:     102400MB
> Image size:      29057MB
>
> Yes, i know it's still possible to create an image which will be compacted
> not that efficiently, but this becomes quite a rare case.
> Do you have such an image? Send it to us.
>
> Thank you.
>
> P.S. in fact we don't need full image in most cases, only metadata is
> essential, so if you worry about data and confidentiality, no problem here:
> # e2image -r /dev/ploopXXp1 - | bzip2 > image.e2i.bz2
>
> --
> Best regards,
>
> Konstantin Khorenko,
> Virtuozzo Linux Kernel Team
>
>
> The /vz partition has also the big advantage of using LVM snapshots and it
>> allows rsync of the container data to another host with less overhead.
>>
>> Also the need to compress the ploop files does not seem to be something
>> I'm willing to do.
>>
>>
>> Regards
>>     Volker
>>
>>
>>> And I want to be able to setup KVM based VMs that have a LVM based disk,
>>>> too.
>>>> In best case KVM VMs can be created from a template, as with the
>>>> container VMs.
>>>>
>>>
>>> Den, is it possible in Vz7?
>>>
>>> Regards
>>>>    Volker
>>>>
>>> _______________________________________________
> Users mailing list
> Users at openvz.org
> https://lists.openvz.org/mailman/listinfo/users
>
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