Merge pull request #43051 from dsavineau/ceph_volume_lvm_migrate_docs

doc/ceph-volume: add lvm migrate/new-db/new-wal

doc/ceph-volume/index.rst

@@ -76,6 +76,9 @@ and ``ceph-disk`` is fully disabled. Encryption is fully supported.
    lvm/systemd
    lvm/list
    lvm/zap
+   lvm/migrate
+   lvm/newdb
+   lvm/newwal
    simple/index
    simple/activate
    simple/scan

doc/ceph-volume/lvm/index.rst

@@ -15,6 +15,12 @@ Implements the functionality needed to deploy OSDs from the ``lvm`` subcommand:
 
 * :ref:`ceph-volume-lvm-list`
 
+* :ref:`ceph-volume-lvm-migrate`
+
+* :ref:`ceph-volume-lvm-newdb`
+
+* :ref:`ceph-volume-lvm-newwal`
+
 .. not yet implemented
 .. * :ref:`ceph-volume-lvm-scan`
 

doc/ceph-volume/lvm/migrate.rst

@@ -0,0 +1,47 @@
+.. _ceph-volume-lvm-migrate:
+
+``migrate``
+===========
+
+Moves BlueFS data from source volume(s) to the target one, source volumes
+(except the main, i.e. data or block one) are removed on success.
+
+LVM volumes are permitted for Target only, both already attached or new one.
+
+In the latter case it is attached to the OSD replacing one of the source
+devices.
+
+Following replacement rules apply (in the order of precedence, stop
+on the first match):
+
+    - if source list has DB volume - target device replaces it.
+    - if source list has WAL volume - target device replaces it.
+    - if source list has slow volume only - operation is not permitted,
+      requires explicit allocation via new-db/new-wal command.
+
+Moves BlueFS data from main device to LV already attached as DB::
+
+    ceph-volume lvm migrate --osd-id 1 --osd-fsid <uuid> --from data --target vgname/db
+
+Moves BlueFS data from shared main device to LV which will be attached as a
+new DB::
+
+    ceph-volume lvm migrate --osd-id 1 --osd-fsid <uuid> --from data --target vgname/new_db
+
+Moves BlueFS data from DB device to new LV, DB is replaced::
+
+    ceph-volume lvm migrate --osd-id 1 --osd-fsid <uuid> --from db --target vgname/new_db
+
+Moves BlueFS data from main and DB devices to new LV, DB is replaced::
+
+    ceph-volume lvm migrate --osd-id 1 --osd-fsid <uuid> --from data db --target vgname/new_db
+
+Moves BlueFS data from main, DB and WAL devices to new LV, WAL is  removed and
+DB is replaced::
+
+    ceph-volume lvm migrate --osd-id 1 --osd-fsid <uuid> --from data db wal --target vgname/new_db
+
+Moves BlueFS data from main, DB and WAL devices to main device, WAL and DB are
+removed::
+
+    ceph-volume lvm migrate --osd-id 1 --osd-fsid <uuid> --from db wal --target vgname/data

doc/ceph-volume/lvm/newdb.rst

@@ -0,0 +1,11 @@
+.. _ceph-volume-lvm-newdb:
+
+``new-db``
+===========
+
+Attaches the given logical volume to OSD as a DB.
+Logical volume name format is vg/lv. Fails if OSD has already got attached DB.
+
+Attach vgname/lvname as a DB volume to OSD 1::
+
+    ceph-volume lvm new-db --osd-id 1 --osd-fsid 55BD4219-16A7-4037-BC20-0F158EFCC83D --target vgname/new_db

doc/ceph-volume/lvm/newwal.rst

@@ -0,0 +1,11 @@
+.. _ceph-volume-lvm-newwal:
+
+``new-wal``
+===========
+
+Attaches the given logical volume to the given OSD as a WAL volume.
+Logical volume format is vg/lv. Fails if OSD has already got attached DB.
+
+Attach vgname/lvname as a WAL volume to OSD 1::
+
+    ceph-volume lvm new-wal --osd-id 1 --osd-fsid 55BD4219-16A7-4037-BC20-0F158EFCC83D --target vgname/new_wal