rbd image association

rbd image association

[Roman Alekseev]

Hi,

Is it possible to associate certain rbd device with the appropriate rbd 
image (for example : image1 > /dev/rbd0)?
We always need to map image1 to /dev/rbd0, image2 to /dev/rbd1 etc. 
Because I'm using /dev/rbd* in some configuration files.

Thanks

-- 
Kind regards,

R. Alekseev

Re: rbd image association

[Roman Alekseev]

On 03.06.2013 11:08, Wolfgang Hennerbichler wrote:
> On Mon, Jun 03, 2013 at 10:52:14AM +0400, Roman Alekseev wrote:
>> Hi,
>>
>> Is it possible to associate certain rbd device with the appropriate
>> rbd image (for example : image1 > /dev/rbd0)?
>> We always need to map image1 to /dev/rbd0, image2 to /dev/rbd1 etc.
>> Because I'm using /dev/rbd* in some configuration files.
> Hi,
>
> I can't remember exactly, but I think there is something like /dev/rbd/<pool>/<imagename> which simply symlinks to /dev/rbdX. This should solve your issue.
>   
>> Thanks
> HTH
> Wolfgang
>
Dear Wolfgang,

I was trying to use the command ln -s /dev/rbd1 image1 but it creates 
wrong symlink. Most likely there is more specific command to symlink the 
image and device correctly.

Thanks.

-- 
Kind regards,

R. Alekseev

Re: rbd image association

[Wido den Hollander]

On 06/03/2013 09:17 AM, Roman Alekseev wrote:
> On 03.06.2013 11:08, Wolfgang Hennerbichler wrote:
>> On Mon, Jun 03, 2013 at 10:52:14AM +0400, Roman Alekseev wrote:
>>> Hi,
>>>
>>> Is it possible to associate certain rbd device with the appropriate
>>> rbd image (for example : image1 > /dev/rbd0)?
>>> We always need to map image1 to /dev/rbd0, image2 to /dev/rbd1 etc.
>>> Because I'm using /dev/rbd* in some configuration files.
>> Hi,
>>
>> I can't remember exactly, but I think there is something like
>> /dev/rbd/<pool>/<imagename> which simply symlinks to /dev/rbdX. This
>> should solve your issue.
>>> Thanks
>> HTH
>> Wolfgang
>>
> Dear Wolfgang,
>
> I was trying to use the command ln -s /dev/rbd1 image1 but it creates
> wrong symlink. Most likely there is more specific command to symlink the
> image and device correctly.
>

Why are you symlinking? Like Wolfgang mentioned, udev takes care of this 
for you.

Just use /dev/rbd/pool/imagename which is created by udev.

> Thanks.
>


-- 
Wido den Hollander
42on B.V.

Phone: +31 (0)20 700 9902
Skype: contact42on

Re: rbd image association

[Roman Alekseev]

On 03.06.2013 11:34, Wido den Hollander wrote:
> udev takes car

Do you mean we need to create some rules in /etc/udev/rules.d/ directory 
and after running rbd -p pool map image my image will be mapped with 
appropriate device?

If so, could you please provide me with the commands which should be 
presented in that file?

Thanks

-- 
Kind regards,

R. Alekseev

Re: rbd image association

[Sage Weil]

On Mon, 3 Jun 2013, Roman Alekseev wrote:
> On 03.06.2013 11:34, Wido den Hollander wrote:
> > udev takes car
> 
> Do you mean we need to create some rules in /etc/udev/rules.d/ directory and
> after running rbd -p pool map image my image will be mapped with appropriate
> device?

The ceph package installs a udev rules file in that directory; you 
shouldn't have to do anything other than the 'rbd map ..' command.  If it 
is not already present, there must be something wrong with the package on 
the platform you are using.  What OS is it?

> 
> If so, could you please provide me with the commands which should be presented
> in that file?
> 
> Thanks
> 
> -- 
> Kind regards,
> 
> R. Alekseev
> 
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

Re: rbd image association

[Roman Alekseev]

On 03.06.2013 18:49, Sage Weil wrote:
> On Mon, 3 Jun 2013, Roman Alekseev wrote:
>> On 03.06.2013 11:34, Wido den Hollander wrote:
>>> udev takes car
>> Do you mean we need to create some rules in /etc/udev/rules.d/ directory and
>> after running rbd -p pool map image my image will be mapped with appropriate
>> device?
> The ceph package installs a udev rules file in that directory; you
> shouldn't have to do anything other than the 'rbd map ..' command.  If it
> is not already present, there must be something wrong with the package on
> the platform you are using.  What OS is it?
>
>> If so, could you please provide me with the commands which should be presented
>> in that file?
>>
>> Thanks
>>
>> -- 
>> Kind regards,
>>
>> R. Alekseev
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
Yep, u're right there is only the file 70-persistent-net.rules in 
/etc/udev/rules.d/ directory.
It is Debian Wheezy 3.2.0-4-amd64

thanks

-- 
Kind regards,

R. Alekseev

Re: rbd image association

[Sage Weil]

On Mon, 3 Jun 2013, Roman Alekseev wrote:
> On 03.06.2013 18:49, Sage Weil wrote:
> > On Mon, 3 Jun 2013, Roman Alekseev wrote:
> > > On 03.06.2013 11:34, Wido den Hollander wrote:
> > > > udev takes car
> > > Do you mean we need to create some rules in /etc/udev/rules.d/ directory
> > > and
> > > after running rbd -p pool map image my image will be mapped with
> > > appropriate
> > > device?
> > The ceph package installs a udev rules file in that directory; you
> > shouldn't have to do anything other than the 'rbd map ..' command.  If it
> > is not already present, there must be something wrong with the package on
> > the platform you are using.  What OS is it?
> > 
> > > If so, could you please provide me with the commands which should be
> > > presented
> > > in that file?
> > > 
> > > Thanks
> > > 
> > > -- 
> > > Kind regards,
> > > 
> > > R. Alekseev
> > > 
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > > 
> > > 
> Yep, u're right there is only the file 70-persistent-net.rules in
> /etc/udev/rules.d/ directory.
> It is Debian Wheezy 3.2.0-4-amd64

The file you want is

	/lib/udev/rules.d/50-rbd.rules

which is part of the librbd1 package.  dpkg -L librbd1 to verify it is 
there...

sage

Re: rbd image association

[Wolfgang Hennerbichler]

On Mon, Jun 03, 2013 at 11:17:16AM +0400, Roman Alekseev wrote:
> Dear Wolfgang,
> 
> I was trying to use the command ln -s /dev/rbd1 image1 but it
> creates wrong symlink. Most likely there is more specific command to
> symlink the image and device correctly.

No, you should not have to do anything manually. I was saying udev should create the symlink for you upon image mapping. If it doesn't, check you udev configuration. It does this for me on ubuntu server. 
 
> Thanks.

Wolfgang

-- 
http://www.wogri.com