[Users] simfs challenge

[Nick Knutov]

Yes, the question is about ploop of course.

How to get metadata of ploop image? `man what`?


28.01.2016 19:04, Konstantin Khorenko пишет:
> Hi Nick,
>
> i believe it's not the question about vzpbackup, but about
> ploop compact which in your case works not that efficient.
>
> Yes, we do work on improving ploop compact and would appreciate in case
> you can provide us metadata of that "bad" ploop image.
>
> Please, file an issue at bugs.openvz.org, i'll post instructions there.
> (No real user data is needed, only fs metadata, which blocks are 
> filled which are not, etc)
>
> Thank you.
>
> -- 
> Best regards,
>
> Konstantin Khorenko,
> Virtuozzo Linux Kernel Team
>
> On 01/28/2016 02:42 PM, Nick Knutov wrote:
>> Hello,
>>
>> One of big reasons to prefer simfs over ploop is disk space overhead in
>> ploop after using snapshots (for backups for example).
>> It can be really huge - we have one CT which takes 120Gb instead of 60Gb
>> (df -h inside) after daily backups with vzpbackup (*) tool. It's
>> after(!) ploop merge & compact.
>>
>> Do you plan to make some improvements for this case?
>>
>> (*) https://github.com/andreasfaerber/vzpbackup
>>
>> 28.01.2016 14:27, Konstantin Khorenko пишет:
>>> Hi All,
>>>
>>> so, this is the current situation with simfs:
>>>
>>> First of all we cannot implement as it was previously (in OpenVZ 6,
>>> 2.6.32-x kernels).
>>> This is because there is no vzfs in Virtuozzo 7, but all quota related
>>> code used by simfs
>>> was shared between vzfs and simfs, and maintaining that code for simfs
>>> only is definitely
>>> not the thing we'd be happy to do.
>>> Yes, we definitely want to reuse some mainstream (or write a
>>> mainstream-able) code for it.
>>>
>>> So, how this could be implemented?
>>>
>>> "Old" simfs fs without quota - is just a bindmount => this is a start
>>> point.
>>> 1st level quota for simfs-based Containers (the quota for the
>>> Container as a whole) can be
>>> implemented using project quota which is going to be accepted to
>>> mainstream sooner or later.
>>>
>>> As for the 2nd level quota (per-user quota inside a CT), we had not
>>> found any good solution
>>> during our internal discussions, so ideas from community are very
>>> welcome.
>>>
>>> So what do we have at the moment: you can create a simfs-based
>>> Container in Virtuozzo 7
>>> (see instructions below), but cannot manage quota for it.
>>>
>>> What should be done further (that's what you can help us with):
>>>
>>> 1. Take project quota kernel patches (which Stas Kinsbursky alredy
>>> ported to vz7 kernel
>>> some time ago), apply them to current vz7 kernel - you'll get the
>>> kernel able to manage
>>> project quota.
>>>
>>> 2. Need to add project quota support to appropriate userspace tools:
>>> quota-tools and e2fsprogs
>>> see details at https://bugs.openvz.org/browse/OVZ-6619
>>>
>>> Hope that helps to understand our plans on simfs in Virtuozzo 7
>>> and looking forward for a hero who could drive this forward! :)
>>>
>>>
>>>
>>> More formal feature description is below:
>>>
>>> =========================================================================================== 
>>>
>>>
>>> 1. Feature
>>> simfs filesystem for Virtuozzo 7 Containers
>>>
>>>
>>> 2. Description
>>> https://bugs.openvz.org/browse/OVZ-6613
>>> https://jira.sw.ru/browse/PSBM-40730
>>>
>>> Differences between recommended Containers disk backend (ploop) and
>>> simfs:
>>> https://openvz.org/CT_storage_backends
>>>
>>> Unlike previous versions of OpenVZ, simfs layout in Virtuozzo 7 is
>>> based on bindmounts.
>>> This means once you start a simfs-based Container, effectively
>>> "private" area of a Container is bindmounted to the "root" Container
>>> area.
>>> That's it.
>>>
>>> How to create a simfs-based Container:
>>> * set VEFSTYPE=simfs in the /etc/vz/vz.conf
>>> # vzctl create $VEID
>>>
>>> 3. Products
>>> Virtuozzo 7, libvzctl-7.0.170
>>>
>>>
>>> 4. Testing
>>> just a validation:
>>> - create a Container
>>> - start/stop the Container
>>> - destroy the Container
>>>
>>> 5. Known issues
>>> * quota for simfs-based Containers is not implemented
>>>    - 1st level quota (for the Container as a whole) is planned to be
>>> implemented via project quota
>>>      https://bugs.openvz.org/browse/OVZ-6619
>>>
>>>    - 2nd level quota (per-user quota inside a Container) is not planned
>>>
>>> * online migration of a simfs-based Container is not implemented
>>>
>>>
>>> 6. Feature owner
>>> Kernel part:    Stanislav Kinsbursky <skinsbursky at virtuozzo.com>
>>> Userspace part: Igor Sukhih <igor at virtuozzo.com>
>>>
>>>
>>> -- 
>>> Best regards,
>>>
>>> Konstantin Khorenko,
>>> Virtuozzo Linux Kernel Team
>>> _______________________________________________
>>> Users mailing list
>>> Users at openvz.org
>>> https://lists.openvz.org/mailman/listinfo/users
>>

-- 
Best Regards,
Nick Knutov
http://knutov.com
ICQ: 272873706
Voice: +7-904-84-23-130