Re: Very unbalanced storage

[Andrew Thompson <andrewkt@aktzero.com>]

On 9/4/2012 11:59 AM, Tommi Virtanen wrote:
> On Fri, Aug 31, 2012 at 11:58 PM, Andrew Thompson <andrewkt@aktzero.com> wrote:
>> Looking at old archives, I found this thread which shows that to mount a
>> pool as cephfs, it needs to be added to mds:
>>
>> http://permalink.gmane.org/gmane.comp.file-systems.ceph.devel/5685
>>
>> I started a `rados cppool data tempstore` a couple hours ago. When it
>> finishes, will I need to remove the current pool from mds somehow(other than
>> just deleting the pool)?
>>
>> Is `ceph mds add_data_pool <poolname>` still required? (It's not listed in
>> `ceph --help`.)
> If the pool you are trying to grow pg_num for really is a CephFS data
> pool, I fear a "rados cppool" is nowhere near enough to perform a
> migration. My understanding is that each of the inodes stored in
> cephfs/on ceph-mds'es knows what pool the file data resides in; you
> shoveling the objects into another pool with "rados cppool" doesn't
> change these pointers, removing the old pool will just break the
> filesystem.
>
> Before we go too far down this road: is your problem pool *really*
> being use as a cephfs data pool? Based on how it's not named "data"
> and you're just now asking about "ceph mds add_data_pool", it seems
> that's not likely..

Well, I guess it's time to wipe this cluster and start over.

Yes, it was my `data` pool I was trying to grow. After renaming and 
removing the original data pool, I can `ls` my folders/files, but not 
access them.

I attempted a tar backup beforehand, so unless it flaked out, I should 
be able to recover data.

I was concerned the small number of PGs created by default by mkcephfs 
would be an issue, so I was trying to up it a bit. I'm not going to have 
100+ OSDs or petabytes of data. I just want a relatively safe place to 
store my files that I can easily extend as needed.

So far, I'm 0 and 5... I keep blowing up the filesystem, one way or another.

-- 
Andrew Thompson
http://aktzero.com/