====== [HOWTO] Completely remove a POOL from cluster ======

^  Documentation  ^|
^Name:| [HOWTO] Completely remove a POOL from cluster |
^Description:|  HOW TO Completely remove a POOL from cluster (hardcore edition) |
^Modification date :|13/06/2018|
^Owner:|dodger|
^Notify changes to:|Owner |
^Tags:|ceph, object storage |
^Scalate to:|The_fucking_bofh|

====== Variables used in this documentation ======

^ Name ^ Description ^ Sample ^
| ''${POOL_NAME}'' | Name of the gw node | <code bash>export POOL_NAME="new.default.rgw.buckets.data"</code> | 

====== Instructions ======

<WRAP center round alert 90%>
Removing a pool will **DESTROY** all the data inside, there will be no way to recover it:
<code>
Error EPERM: WARNING: this will *PERMANENTLY DESTROY* all data stored in pool new.default.rgw.buckets.data.  If you are *ABSOLUTELY CERTAIN* that is what you want, pass the pool name *twice*, followed by --yes-i-really-really-mean-it.
</code>
</WRAP>


Droping a pool:
<code bash>
ceph osd pool delete ${POOL_NAME}
</code>

Will result in the upper message:
<code>
Error EPERM: WARNING: this will *PERMANENTLY DESTROY* all data stored in pool ${POOL_NAME}.  If you are *ABSOLUTELY CERTAIN* that is what you want, pass the pool name *twice*, followed by --yes-i-really-really-mean-it.
</code>

So:
<code bash>
ceph osd pool delete ${POOL_NAME} ${POOL_NAME} --yes-i-really-really-mean-it
</code>

That by default will show a message:
<code>
Error EPERM: pool deletion is disabled; you must first set the mon_allow_pool_delete config option to true before you can destroy a pool
</code>

So you need to change that parameter prior to dropping the pool:
<code bash>
ceph tell mon.${x} injectargs '--mon-allow-pool-delete=true' 
</code>

Where ''${x}'' is the master monitor (I suppose any ''mon'' on the pool will propagate the setting).
\\
Then drop the pool:
\\
<code bash>
ceph osd pool delete ${POOL_NAME} ${POOL_NAME} --yes-i-really-really-mean-it
</code>
\\
And re-set the parameter, **THIS IS MANDATORY**:
<code bash>
ceph tell mon.${x} injectargs '--mon-allow-pool-delete=false' 
</code>