[Users] OpenVZ and ZFS excellent experience

[Pavel Odintsov]

And I checked my containers with 200% disk overuse from first message
and got negative result. 24Gb of wasted space is not related with
cluster size issue.

./ploop_gramentation_checker.py /vz/private/41507/root.hdd/root.hdd
We count 43285217280 bytes
We count 6079506655 zero bytes
We count 37205710625 non zero bytes
We have 14.045226 % of space lost due to ploop fragmentation

On Sun, Jan 11, 2015 at 7:45 PM, Pavel Odintsov
<pavel.odintsov at gmail.com> wrote:
> Hello, folks!
>
> I read your message again and found suggestion about decreasing block
> size of ploop. But unfortunately it's not possible with vzctl in any
> ways. We can do it only with direct call of ploop.
>
> Because I can't change block size or recreate VE with another block
> size I tried to do some research about space lost with current block
> size.
>
> I wrote tool for checking amount of wasted space in ploop:
> https://gist.github.com/pavel-odintsov/d5c37316e538908e0f01
>
> Sorry, I'm not a good pythoner and any
> feedback/hate/complains/optimizations about this code are welcome.
>
> Everyone can check how many space it can save if reduce ploop block size.
>
> Some data from me:
>
> We count 5276434432 bytes
> We count 1360051876 zero bytes
> We count 3916382556 non zero bytes
> We have 25.775965 % of space lost due to ploop fragmentation
>
> We count 1105199104 bytes
> We count 509808990 zero bytes
> We count 595390114 non zero bytes
> We have 46.128249 % of space lost due to ploop fragmentation
>
> On Sat, Jan 10, 2015 at 5:50 PM, Pavel Odintsov
> <pavel.odintsov at gmail.com> wrote:
>> Hello!
>>
>> Thank you! I will contact with you out off list.
>>
>> On Sat, Jan 10, 2015 at 4:44 PM, Kirill Korotaev <dev at parallels.com> wrote:
>>> Pavel,
>>>
>>> it’s impossible to analyze it just by `du` and `df` output, so please give me access if you want me to take a look into it.
>>> (e.g. if I would create 10 million of 1KB files du would show me 10GB while ext4 (and most other file systems) would allocate 40GB in reality assuming 4KB block size)
>>>
>>> Thanks,
>>> Kirill
>>>
>>>
>>>> On 10 Jan 2015, at 00:54, Pavel Odintsov <pavel.odintsov at gmail.com> wrote:
>>>>
>>>> Thank you, Kirill! I am grateful for your answer!
>>>>
>>>> I reproduced this issue specially for you on one container with 2.4
>>>> times (240% vs 20%) overuse.
>>>>
>>>> I do my tests with current vzctl and ploop 1.12.2 (with fixed
>>>> http://bugzilla.openvz.org/show_bug.cgi?id=3156).
>>>>
>>>> Please check this gist:
>>>> https://gist.github.com/pavel-odintsov/b2162c0f7588bb8e5c15
>>>>
>>>> I can't describe this behavior without complying on ext4 data.... But
>>>> I I will be very happy if you fix it :)
>>>>
>>>> On Sat, Jan 10, 2015 at 12:29 AM, Kirill Korotaev <dev at parallels.com> wrote:
>>>>>
>>>>>> On 09 Jan 2015, at 21:39, Pavel Odintsov <pavel.odintsov at gmail.com> wrote:
>>>>>>
>>>>>> Hello, everybody!
>>>>>>
>>>>>> Do somebody have any news about ZFS and OpenVZ experience?
>>>>>>
>>>>>> Why not?
>>>>>>
>>>>>> Did you checked my comparison table for simfs vs ploop vs ZFS volumes?
>>>>>> You should do it ASAP:
>>>>>> https://github.com/pavel-odintsov/OpenVZ_ZFS/blob/master/openvz_storage_backends.md
>>>>>>
>>>>>> Still not interesting?
>>>>>>
>>>>>> For example if you have 5Tb disk array (used up to 90%) and using
>>>>>> ploop now you lose about 800GB of disk space!
>>>>>
>>>>> Well, AFAIR we simply have a threshold that ploop is not compacted until it’s size is 20% bigger then it should be…
>>>>> Also you can try smaller ploop block size. Anyway, my point is that it has nothing to do with ext4 metadata as stated in your table.
>>>>>
>>>>>
>>>>>> This data is from real HWN with few hundreds of containers.
>>>>>>
>>>>>> I have excellent experience and very good news about ZFS! ZFS on Linux
>>>>>> team will add very important feature, linux quota inside container
>>>>>> (more details here https://github.com/zfsonlinux/zfs/pull/2577
>>>>>>
>>>>>> But still no news about ZFS from OpenVZ team (and even from Virtuozza
>>>>>> Core) and we can work separately :)
>>>>>>
>>>>>> Fortunately, we do not need any support from vzctl and can use "raw
>>>>>> vzctl" with some lightweight manuals from my repo:
>>>>>> https://github.com/pavel-odintsov/OpenVZ_ZFS/blob/master/OpenVZ_containers_on_zfs_filesystem.md
>>>>>>
>>>>>> I collected all useful information here
>>>>>> https://github.com/pavel-odintsov/OpenVZ_ZFS
>>>>>>
>>>>>> Stay tuned! Join to us!
>>>>>>
>>>>>> --
>>>>>> Sincerely yours, Pavel Odintsov
>>>>>> _______________________________________________
>>>>>> Users mailing list
>>>>>> Users at openvz.org
>>>>>> https://lists.openvz.org/mailman/listinfo/users
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Users mailing list
>>>>> Users at openvz.org
>>>>> https://lists.openvz.org/mailman/listinfo/users
>>>>
>>>>
>>>>
>>>> --
>>>> Sincerely yours, Pavel Odintsov
>>>>
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>>>> https://lists.openvz.org/mailman/listinfo/users
>>>
>>>
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>>> Users mailing list
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>>
>>
>>
>> --
>> Sincerely yours, Pavel Odintsov
>
>
>
> --
> Sincerely yours, Pavel Odintsov



-- 
Sincerely yours, Pavel Odintsov