doc: add cephfs base documentation

doc/ceph/README.md

@@ -0,0 +1,51 @@
+# managing ceph
+
+Always refer back to the official documentation at https://docs.ceph.com/en/latest
+
+## adding new cephfs
+- create a erasure code profile which will allow you to customise the raid level
+    - raid5 with 3 disks? k=2,m=1
+    - raid5 with 6 disks? k=5,m=1
+    - raid6 with 4 disks? k=2,m=2, etc
+- create osd pool using custom profile for data
+- create osd pool using default replicated profile for metadata
+- enable ec_overwrites for the data pool
+- create the ceph fs volume using data/metadata pools
+- set ceph fs settings
+    - specify minimum number of metadata servers (mds)
+    - set fs to be for bulk data
+    - set mds fast failover with standby reply
+
+
+    sudo ceph osd erasure-code-profile set ec_4_1 k=4 m=1
+    sudo ceph osd pool create media_data 128 erasure ec_4_1
+    sudo ceph osd pool create media_metadata 32 replicated_rule
+    sudo ceph osd pool set media_data allow_ec_overwrites true
+    sudo ceph osd pool set media_data bulk true
+    sudo ceph fs new mediafs media_metadata media_data --force
+    sudo ceph fs set mediafs allow_standby_replay true
+    sudo ceph fs set mediafs max_mds 2
+
+
+## creating authentication tokens
+
+- this will create a client keyring named media
+- this client will have the following capabilities:
+    - mon: read
+    - mds:
+        - read /
+        - read/write /media
+        - read/write /common
+    - osd: read/write to cephfs_data pool
+
+    sudo ceph auth get-or-create client.media mon 'allow r' mds 'allow r path=/, allow rw path=/media, allow rw path=/common' osd 'allow rw pool=cephfs_data'
+
+## list the authentication tokens and permissions
+
+    ceph auth ls
+
+## change the capabilities of a token
+
+this will overwrite the current capabilities of a given client.user
+
+    sudo ceph auth caps client.media mon 'allow r' mds 'allow rw path=/' osd 'allow rw pool=media_data'