Bug 2065732

1) In 4.x guide we have a note regarding this feature - 
>>`By default, you must protect the snapshot before you can clone it. To 
avoid having to protect the snapshot before you clone it, set ceph osd set-require-min-compat-client mimic. You can set it to higher versions than mimic as well.`

We need to add it to 5.x guide also

2) information on --rbd-default-clone-format is that if user has not set set-require-min-compat-client to greater than or equal to mimic, user can use `--rbd-default-clone-format 2` with rbd clone command to create clone of version 2
but using --rbd-default-clone-format per image basis is not recommended - Ref - https://bugzilla.redhat.com/show_bug.cgi?id=2065592#c1

3) in protecting snapshot section, we need to mention that snapshot need not to be protected to be able to create clone as clone v2 is doesn't need snapshot to be protected.

4) We need to mention that is set-require-min-compat-client is greater than or equal to mimic, by default clone v2 would be created.
but clients older than mimic won't be able to access those RBD images.

working steps for this feature for reference- we can assess what needs to be documented and list the steps in the doc accordingly

[ceph: root@magna021 /]# ceph osd pool create test1 128
pool 'test1' created
[ceph: root@magna021 /]# ceph osd pool application enable test1 rbd
enabled application 'rbd' on pool 'test1'
[ceph: root@magna021 /]# rbd pool init -p test1

[ceph: root@magna021 /]# rbd create --size 1024 test1/image1 --thick-provision --debug-rbd 0 
Thick provisioning: 100% complete...done.
[ceph: root@magna021 /]# ceph osd lspools
1 .rgw.root
2 device_health_metrics
4 pmem
5 nonpmem
6 test_io
8 pmem1
16 replicapool
17 pmem2
22 rbd-mirror_rep_pool
23 smaple_pool
24 iscsipool
25 test
26 test1
[ceph: root@magna021 /]# rbd snap create test1/image1@snap --debug-rbd 0
Creating snap: 100% complete...done.
[ceph: root@magna021 /]# ceph osd set-require-min-compat-client mimic
set require_min_compat_client to mimic
[ceph: root@magna021 /]# ceph config set client rbd_move_parent_to_trash_on_remove true (diable if rbd_move_to_trash_on_remove is enabled in client)-not compatible
[ceph: root@magna021 /]# ceph config get client
WHO     MASK  LEVEL     OPTION                              VALUE                                                                                                                         RO
global        basic     container_image                     registry-proxy.engineering.redhat.com/rh-osbs/rhceph@sha256:141e439ccbca0d3ed3cd4be9332f09575f6450e04cef5127d625d403fdfbb3cb  * 
client        advanced  debug_rbd                           30/30                                                                                                                           
client        advanced  debug_rbd_mirror                    30/30                                                                                                                           
client        basic     log_file                            /var/log/ceph/client.log                                                                                                      * 
client        basic     log_to_file                         true                                                                                                                            
client        basic     rbd_move_parent_to_trash_on_remove  true                                                                                                                            
client        basic     rbd_move_to_trash_on_remove         true                                                                                                                            
client        advanced  rbd_persistent_cache_size           1073741824                                                                                                                      
[ceph: root@magna021 /]# rbd clone test1/image1@snap test1/child --debug-rbd 0
[ceph: root@magna021 /]# rbd snap rm test1/image1@snap --debug-rbd 0

[ceph: root@magna021 /]# rbd rm test1/image1 --debug-rbd 0
Removing image: 100% complete...done.
[ceph: root@magna021 /]# rbd trash list test1 --debug-rbd 0
13b99caee1fdb7 image1
[ceph: root@magna021 /]# rbd flatten test1/child --debug-rbd 0
Image flatten: 100% complete...done.
[ceph: root@magna021 /]# rbd trash list test1 --debug-rbd 0

[ceph: root@magna021 /]#

Content looks good to me. Moving to verified state.