Ceph

Going from top to bottom in the 'configure a master region' section in 'create pools' (http://ceph.com/docs/master/radosgw/federated-config/#create-pools) it is unclear to me
where do I need to do that.

Each instance? Is one instance per cluster? If so, I need to create these pools in one cluster or in both?

As a new user, I have no idea what a pool is, so I follow the links to understand what they are and how to configure them. But that is a lot of information.

Detailed information is good, but for setting up this, do I need to understand every single detail on how to configure a federated gateway? Can't we push the
more verbose information for later? What is the least amount of information I need to move forward?

After going through the details of pools, it does seem like I am required to have knowledge on:

• pg-num
• pgp-num
• replicated vs erasure
• erasure-code-profile
• ruleset-name
• ruleset-number

In the http://docs.ceph.com/docs/master/rados/operations/pools/#create-a-pool section, I am asked to " refer to the Pool, PG and CRUSH Config Reference" before creating them.

That is now three levels deep of highly detailed information I am not sure I need (or want to grasp all at once).

In the config reference for pools there are several links for yet another level of reference, for example to understand what a `pg-num` is, which seems important as the description says that the default is not suitable.

At this point I have five tabs open with docs and still unsure what is the least minimum I need to get things going:

http://docs.ceph.com/docs/master/radosgw/config-ref/#pools
http://docs.ceph.com/docs/master/rados/configuration/pool-pg-config-ref/
http://docs.ceph.com/docs/master/rados/operations/placement-groups/
http://docs.ceph.com/docs/master/rados/operations/pools/#create-a-pool
http://ceph.com/docs/master/radosgw/federated-config/#create-pools

All of this when the documentation said:

See Configuration Reference - Pools for details on the default pools for gateways. See Pools for details on creating pools. Execute the following to create a pool:

And then followed by a command which implies I need to understand all of the variables, since it is instructing the user, imperatively, to run that command:

ceph osd pool create {poolname} {pg-num} {pgp-num} {replicated | erasure} [{erasure-code-profile}]  {ruleset-name} {ruleset-number}