mirror of
https://github.com/ceph/ceph
synced 2024-12-22 11:31:55 +00:00
93 lines
2.7 KiB
ReStructuredText
93 lines
2.7 KiB
ReStructuredText
Upgrading the MDS Cluster
|
|
=========================
|
|
|
|
Currently the MDS cluster does not have built-in versioning or file system
|
|
flags to support seamless upgrades of the MDSs without potentially causing
|
|
assertions or other faults due to incompatible messages or other functional
|
|
differences. For this reason, it's necessary during any cluster upgrade to
|
|
reduce the number of active MDS for a file system to one first so that two
|
|
active MDS do not communicate with different versions. Further, it's also
|
|
necessary to take standbys offline as any new CompatSet flags will propogate
|
|
via the MDSMap to all MDS and cause older MDS to suicide.
|
|
|
|
The proper sequence for upgrading the MDS cluster is:
|
|
|
|
1. Reduce the number of ranks to 1:
|
|
|
|
::
|
|
|
|
ceph fs set <fs_name> max_mds 1
|
|
|
|
2. Wait for cluster to deactivate non-zero ranks where only rank 0 is active and the rest are standbys.
|
|
|
|
::
|
|
|
|
ceph status # wait for MDS to finish stopping
|
|
|
|
3. Take all standbys offline, e.g. using systemctl:
|
|
|
|
::
|
|
|
|
systemctl stop ceph-mds.target
|
|
|
|
4. Confirm only one MDS is online and is rank 0 for your FS:
|
|
|
|
::
|
|
|
|
ceph status
|
|
|
|
5. Upgrade the single active MDS, e.g. using systemctl:
|
|
|
|
::
|
|
|
|
# use package manager to update cluster
|
|
systemctl restart ceph-mds.target
|
|
|
|
6. Upgrade/start the standby daemons.
|
|
|
|
::
|
|
|
|
# use package manager to update cluster
|
|
systemctl restart ceph-mds.target
|
|
|
|
7. Restore the previous max_mds for your cluster:
|
|
|
|
::
|
|
|
|
ceph fs set <fs_name> max_mds <old_max_mds>
|
|
|
|
|
|
Upgrading pre-Firefly filesystems past Jewel
|
|
============================================
|
|
|
|
.. tip::
|
|
|
|
This advice only applies to users with filesystems
|
|
created using versions of Ceph older than *Firefly* (0.80).
|
|
Users creating new filesystems may disregard this advice.
|
|
|
|
Pre-firefly versions of Ceph used a now-deprecated format
|
|
for storing CephFS directory objects, called TMAPs. Support
|
|
for reading these in RADOS will be removed after the Jewel
|
|
release of Ceph, so for upgrading CephFS users it is important
|
|
to ensure that any old directory objects have been converted.
|
|
|
|
After installing Jewel on all your MDS and OSD servers, and restarting
|
|
the services, run the following command:
|
|
|
|
::
|
|
|
|
cephfs-data-scan tmap_upgrade <metadata pool name>
|
|
|
|
This only needs to be run once, and it is not necessary to
|
|
stop any other services while it runs. The command may take some
|
|
time to execute, as it iterates overall objects in your metadata
|
|
pool. It is safe to continue using your filesystem as normal while
|
|
it executes. If the command aborts for any reason, it is safe
|
|
to simply run it again.
|
|
|
|
If you are upgrading a pre-Firefly CephFS filesystem to a newer Ceph version
|
|
than Jewel, you must first upgrade to Jewel and run the ``tmap_upgrade``
|
|
command before completing your upgrade to the latest version.
|
|
|