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diff --git a/src/ceph/doc/rados/operations/upmap.rst b/src/ceph/doc/rados/operations/upmap.rst deleted file mode 100644 index 58f6322..0000000 --- a/src/ceph/doc/rados/operations/upmap.rst +++ /dev/null @@ -1,75 +0,0 @@ -Using the pg-upmap -================== - -Starting in Luminous v12.2.z there is a new *pg-upmap* exception table -in the OSDMap that allows the cluster to explicitly map specific PGs to -specific OSDs. This allows the cluster to fine-tune the data -distribution to, in most cases, perfectly distributed PGs across OSDs. - -The key caveat to this new mechanism is that it requires that all -clients understand the new *pg-upmap* structure in the OSDMap. - -Enabling --------- - -To allow use of the feature, you must tell the cluster that it only -needs to support luminous (and newer) clients with:: - - ceph osd set-require-min-compat-client luminous - -This command will fail if any pre-luminous clients or daemons are -connected to the monitors. You can see what client versions are in -use with:: - - ceph features - -A word of caution ------------------ - -This is a new feature and not very user friendly. At the time of this -writing we are working on a new `balancer` module for ceph-mgr that -will eventually do all of this automatically. - -Until then, - -Offline optimization --------------------- - -Upmap entries are updated with an offline optimizer built into ``osdmaptool``. - -#. Grab the latest copy of your osdmap:: - - ceph osd getmap -o om - -#. Run the optimizer:: - - osdmaptool om --upmap out.txt [--upmap-pool <pool>] [--upmap-max <max-count>] [--upmap-deviation <max-deviation>] - - It is highly recommended that optimization be done for each pool - individually, or for sets of similarly-utilized pools. You can - specify the ``--upmap-pool`` option multiple times. "Similar pools" - means pools that are mapped to the same devices and store the same - kind of data (e.g., RBD image pools, yes; RGW index pool and RGW - data pool, no). - - The ``max-count`` value is the maximum number of upmap entries to - identify in the run. The default is 100, but you may want to make - this a smaller number so that the tool completes more quickly (but - does less work). If it cannot find any additional changes to make - it will stop early (i.e., when the pool distribution is perfect). - - The ``max-deviation`` value defaults to `.01` (i.e., 1%). If an OSD - utilization varies from the average by less than this amount it - will be considered perfect. - -#. The proposed changes are written to the output file ``out.txt`` in - the example above. These are normal ceph CLI commands that can be - run to apply the changes to the cluster. This can be done with:: - - source out.txt - -The above steps can be repeated as many times as necessary to achieve -a perfect distribution of PGs for each set of pools. - -You can see some (gory) details about what the tool is doing by -passing ``--debug-osd 10`` to ``osdmaptool``. |