How to know the Rados pools path.

How to know the Rados pools path.

[ramu]

Hi,

      Iam creating rados pools from java-rados,it's creating the pool fine.
I don't know this pool location on disks,please help me to know the location
of rados pool(means path).It is showing the list of pools from the command 
"rados lspools".But there is not showing the path.

Thanks,
Ramu.

Re: How to know the Rados pools path.

[Wido den Hollander]

On 08/16/2012 02:20 PM, ramu wrote:
> Hi,
>
>        Iam creating rados pools from java-rados,it's creating the pool fine.
> I don't know this pool location on disks,please help me to know the location
> of rados pool(means path).It is showing the list of pools from the command
> "rados lspools".But there is not showing the path.
>

Why do you want to know the pool location?

First, there is no such hardcoded location. On the disk of an OSD you'll 
find directories for each PG with their files in them, but I wouldn't 
recommended digging in there.

There is no need for it. You know the pool name and you can interact 
with your objects.

Wido

> Thanks,
> Ramu.
>
>
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Re: How to know the Rados pools path.

[Gregory Farnum]

On Thursday, August 16, 2012, Wido den Hollander wrote:
>
> On 08/16/2012 02:20 PM, ramu wrote:
>>
>> Hi,
>>
>>        Iam creating rados pools from java-rados,it's creating the pool fine.
>> I don't know this pool location on disks,please help me to know the location
>> of rados pool(means path).It is showing the list of pools from the command
>> "rados lspools".But there is not showing the path.
>>
>
> Why do you want to know the pool location?
>
> First, there is no such hardcoded location. On the disk of an OSD you'll find directories for each PG with their files in them, but I wouldn't recommended digging in there.


To expand on this a little: a pool does not exist in a single
location. It's sharded into placement groups (PGs), which are then
distributed across the OSDs -- but they can and do move in response to
changing cluster conditions. :)

If you mean that you're trying to mount a rados pool in linux, it
doesn't work like that. RADOS pools are closer to S3 buckets than to a
LUN or a filesystem volume...
-Greg

Re: How to know the Rados pools path.

[ramu]

Hi all,

    Thank u for your reply,Is there any option for the created pool is
 mounting to another volume.

Thanks,
Ramu.

Re: How to know the Rados pools path.

[Tommi Virtanen]

On Thu, Aug 16, 2012 at 9:31 PM, ramu <ramu.freesystems@gmail.com> wrote:
>     Thank u for your reply,Is there any option for the created pool is
>  mounting to another volume.

RADOS pools are not filesystems. They cannot be mounted.

The Ceph Distributed File System stores it's metadata in one pool
(default "metadata") and data in one or more pools (default "data"),
but that is more like a database that is actually stored in a file --
that doesn't mean every file knows SQL.