Problem when creating snashots

Problem when creating snashots

[The MoonSeeker]

Hi,

I'd like to create many snaphot of an image but I've got when I  
attemp to create the 32th snapshot :

root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
   Rounding up size to full physical extent 152.00 MB
   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
   Failed to suspend origin vps-core

I don't understand the error..

This what I get when scaning the LVM :

root@B03-PC:/diplome# lvscan
   ACTIVE   Original '/dev/openvz/vps-core' [200.00 MB] inherit
   ACTIVE            '/dev/openvz/232' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/201' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/202' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/203' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/204' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/205' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/206' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/207' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/208' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/209' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/210' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/211' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/212' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/213' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/214' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/215' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/216' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/217' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/218' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/219' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/220' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/221' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/222' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/223' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/224' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/225' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/226' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/227' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/228' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/229' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/230' [152.00 MB] inherit
   ACTIVE   Snapshot '/dev/openvz/231' [152.00 MB] inherit

What can I do? Is it some limitation when snapshoting?

Info :

root@B03:/diplome# uname -r
2.6.16-026test014

Thank you

Re: Problem when creating snashots

[Jan Blunck]

On Tue, Sep 26, The MoonSeeker wrote:

> I'd like to create many snaphot of an image but I've got when I  
> attemp to create the 32th snapshot :
> 
> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
>   Rounding up size to full physical extent 152.00 MB
>   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
>   Failed to suspend origin vps-core
> 
> I don't understand the error..

I'm not a native french speaker (hint!) but I assume you run out of
memory.

Yes there are limitations to the number of snapshots. For every single
snapshot we have to allocate memory for copying the chunks to the exception
store.

Do you really need that many snapshots at the same time?

Re: Problem when creating snashots

[The MoonSeeker]

Yes I really need it. I have to create a virtual network editor for  
my diploma project. So I have found many virtual solutions but the  
bestest for our project is OpenVZ. Unfortunatly, OpenVZ don't offer  
the copy on write with his solution, after many tests, I have found a  
solution based on LVM.

The main idea is to have a Virtual Private Server Core and lot of  
Virtual Private Server who are a snapshot of the Virtual Server Core.  
Now the problem is the limitation of VLM, I need more than 32 servers  
(32 snapshots). Will this limitation incresed in futur futur released  
of LVM? Or can we broke this limitation?

Have you a solution, it's relly urgent for me...

Thanks you


Le 26 sept. 06 à 23:14, Jan Blunck a écrit :

> On Tue, Sep 26, The MoonSeeker wrote:
>
>> I'd like to create many snaphot of an image but I've got when I
>> attemp to create the 32th snapshot :
>>
>> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
>>   Rounding up size to full physical extent 152.00 MB
>>   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
>>   Failed to suspend origin vps-core
>>
>> I don't understand the error..
>
> I'm not a native french speaker (hint!) but I assume you run out of
> memory.
>
> Yes there are limitations to the number of snapshots. For every single
> snapshot we have to allocate memory for copying the chunks to the  
> exception
> store.
>
> Do you really need that many snapshots at the same time?
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel

Re: Problem when creating snashots

[Bernd Zeimetz]

Hi,
>
> I'd like to create many snaphot of an image but I've got when I attemp 
> to create the 32th snapshot :
>
> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
>   Rounding up size to full physical extent 152.00 MB
>   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
>   Failed to suspend origin vps-core
do you probably run into the bug mentioned in
https://www.redhat.com/archives/dm-devel/2006-September/msg00058.html



Best regards,

Bernd Zeimetz

Re: Problem when creating snashots

[Milan Broz]

The problem with limited number of snapshots is caused by the using
big common mempool in dm-io module.
(This can happen even you have a lot of free memory...)

There are new dm-io patches which introduce new dm-io interface
(using private mempools) and solving this type of snapshot limitation.

Patches are currently in review and will probably change a bit,
but I hope it will in 2.6.19 kernel.

Milan

--
mbroz@redhat.com

The MoonSeeker napsal(a):
> Yes I really need it. I have to create a virtual network editor for my
> diploma project. So I have found many virtual solutions but the bestest
> for our project is OpenVZ. Unfortunatly, OpenVZ don't offer the copy on
> write with his solution, after many tests, I have found a solution based
> on LVM.
> 
> The main idea is to have a Virtual Private Server Core and lot of
> Virtual Private Server who are a snapshot of the Virtual Server Core.
> Now the problem is the limitation of VLM, I need more than 32 servers
> (32 snapshots). Will this limitation incresed in futur futur released of
> LVM? Or can we broke this limitation?
> 
> Have you a solution, it's relly urgent for me...
> 
> Thanks you
> 
> 
> Le 26 sept. 06 à 23:14, Jan Blunck a écrit :
> 
>> On Tue, Sep 26, The MoonSeeker wrote:
>>
>>> I'd like to create many snaphot of an image but I've got when I
>>> attemp to create the 32th snapshot :
>>>
>>> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
>>>   Rounding up size to full physical extent 152.00 MB
>>>   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
>>>   Failed to suspend origin vps-core
>>>
>>> I don't understand the error..
>>
>> I'm not a native french speaker (hint!) but I assume you run out of
>> memory.
>>
>> Yes there are limitations to the number of snapshots. For every single
>> snapshot we have to allocate memory for copying the chunks to the
>> exception
>> store.
>>
>> Do you really need that many snapshots at the same time?
>>
>> -- 
>> dm-devel mailing list
>> dm-devel@redhat.com
>> https://www.redhat.com/mailman/listinfo/dm-devel
> 
> 
> -- 
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel

Re: Problem when creating snashots

[The MoonSeeker]

Where can I find this patch? I'd like to test it..

Le 27 sept. 06 à 12:36, Milan Broz a écrit :

> The problem with limited number of snapshots is caused by the using
> big common mempool in dm-io module.
> (This can happen even you have a lot of free memory...)
>
> There are new dm-io patches which introduce new dm-io interface
> (using private mempools) and solving this type of snapshot limitation.
>
> Patches are currently in review and will probably change a bit,
> but I hope it will in 2.6.19 kernel.
>
> Milan
>
> --
> mbroz@redhat.com
>
> The MoonSeeker napsal(a):
>> Yes I really need it. I have to create a virtual network editor  
>> for my
>> diploma project. So I have found many virtual solutions but the  
>> bestest
>> for our project is OpenVZ. Unfortunatly, OpenVZ don't offer the  
>> copy on
>> write with his solution, after many tests, I have found a solution  
>> based
>> on LVM.
>>
>> The main idea is to have a Virtual Private Server Core and lot of
>> Virtual Private Server who are a snapshot of the Virtual Server Core.
>> Now the problem is the limitation of VLM, I need more than 32 servers
>> (32 snapshots). Will this limitation incresed in futur futur  
>> released of
>> LVM? Or can we broke this limitation?
>>
>> Have you a solution, it's relly urgent for me...
>>
>> Thanks you
>>
>>
>> Le 26 sept. 06 à 23:14, Jan Blunck a écrit :
>>
>>> On Tue, Sep 26, The MoonSeeker wrote:
>>>
>>>> I'd like to create many snaphot of an image but I've got when I
>>>> attemp to create the 32th snapshot :
>>>>
>>>> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
>>>>   Rounding up size to full physical extent 152.00 MB
>>>>   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
>>>>   Failed to suspend origin vps-core
>>>>
>>>> I don't understand the error..
>>>
>>> I'm not a native french speaker (hint!) but I assume you run out of
>>> memory.
>>>
>>> Yes there are limitations to the number of snapshots. For every  
>>> single
>>> snapshot we have to allocate memory for copying the chunks to the
>>> exception
>>> store.
>>>
>>> Do you really need that many snapshots at the same time?
>>>
>>> -- 
>>> dm-devel mailing list
>>> dm-devel@redhat.com
>>> https://www.redhat.com/mailman/listinfo/dm-devel
>>
>>
>> -- 
>> dm-devel mailing list
>> dm-devel@redhat.com
>> https://www.redhat.com/mailman/listinfo/dm-devel
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel

Re: Problem when creating snashots

[The MoonSeeker]

Yes I have already check this bug but it can't solve my problem..

I create a bug : https://bugzilla.redhat.com/bugzilla/show_bug.cgi? 
id=208172

I test the option -c of lvcreate but the problem is the same..

Regards

Le 27 sept. 06 à 12:03, Bernd Zeimetz a écrit :

> Hi,
>>
>> I'd like to create many snaphot of an image but I've got when I  
>> attemp to create the 32th snapshot :
>>
>> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
>>   Rounding up size to full physical extent 152.00 MB
>>   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
>>   Failed to suspend origin vps-core
> do you probably run into the bug mentioned in
> https://www.redhat.com/archives/dm-devel/2006-September/msg00058.html
>
>
>
> Best regards,
>
> Bernd Zeimetz
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel

Re: Problem when creating snashots

[Jan Blunck]

On Wed, Sep 27, The MoonSeeker wrote:

> Where can I find this patch? I'd like to test it..
> 

Take a look at:

http://www.kernel.org/pub/linux/kernel/people/agk/patches/2.6/editing/

Re: Problem when creating snashots

[Milan Broz]

The MoonSeeker napsal(a):
> Where can I find this patch? I'd like to test it..
> 

Patches are in development quilt queue 
http://www.kernel.org/pub/linux/kernel/people/agk/patches/2.6/editing/

related *testing* patches 
dm-io-*.patch
dm-kcopyd-newio.patch
dm-exception-store-newio.patch

but depends probably on some patches in series file.

Note: there is no patch for new dm-io change in dm-raid1 & dm-log,
do *not* use these patches now if you are using mirror (raid1)
target ! 
(Remaining patches - including raid1 - are waiting in Alasdair's mail...)

Milan
--
mbroz@redhat.com

> Le 27 sept. 06 à 12:36, Milan Broz a écrit :
> 
>> The problem with limited number of snapshots is caused by the using
>> big common mempool in dm-io module.
>> (This can happen even you have a lot of free memory...)
>>
>> There are new dm-io patches which introduce new dm-io interface
>> (using private mempools) and solving this type of snapshot limitation.
>>
>> Patches are currently in review and will probably change a bit,
>> but I hope it will in 2.6.19 kernel.
>>
>> Milan
>>
>> -- 
>> mbroz@redhat.com
>>
>> The MoonSeeker napsal(a):
>>> Yes I really need it. I have to create a virtual network editor for my
>>> diploma project. So I have found many virtual solutions but the bestest
>>> for our project is OpenVZ. Unfortunatly, OpenVZ don't offer the copy on
>>> write with his solution, after many tests, I have found a solution based
>>> on LVM.
>>>
>>> The main idea is to have a Virtual Private Server Core and lot of
>>> Virtual Private Server who are a snapshot of the Virtual Server Core.
>>> Now the problem is the limitation of VLM, I need more than 32 servers
>>> (32 snapshots). Will this limitation incresed in futur futur released of
>>> LVM? Or can we broke this limitation?
>>>
>>> Have you a solution, it's relly urgent for me...
>>>
>>> Thanks you
>>>
>>>
>>> Le 26 sept. 06 à 23:14, Jan Blunck a écrit :
>>>
>>>> On Tue, Sep 26, The MoonSeeker wrote:
>>>>
>>>>> I'd like to create many snaphot of an image but I've got when I
>>>>> attemp to create the 32th snapshot :
>>>>>
>>>>> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core
>>>>>   Rounding up size to full physical extent 152.00 MB
>>>>>   device-mapper: reload ioctl failed: Ne peut allouer de la mémoire
>>>>>   Failed to suspend origin vps-core
>>>>>
>>>>> I don't understand the error..
>>>>
>>>> I'm not a native french speaker (hint!) but I assume you run out of
>>>> memory.
>>>>
>>>> Yes there are limitations to the number of snapshots. For every single
>>>> snapshot we have to allocate memory for copying the chunks to the
>>>> exception
>>>> store.
>>>>
>>>> Do you really need that many snapshots at the same time?