:orphan: .. _osdmaptool: ====================================================== osdmaptool -- ceph osd cluster map manipulation tool ====================================================== .. program:: osdmaptool Synopsis ======== | **osdmaptool** *mapfilename* [--print] [--createsimple *numosd* [--pgbits *bitsperosd* ] ] [--clobber] | **osdmaptool** *mapfilename* [--import-crush *crushmap*] | **osdmaptool** *mapfilename* [--export-crush *crushmap*] | **osdmaptool** *mapfilename* [--upmap *file*] [--upmap-max *max-optimizations*] [--upmap-deviation *max-deviation*] [--upmap-pool *poolname*] [--save] [--upmap-active] | **osdmaptool** *mapfilename* [--upmap-cleanup] [--upmap *file*] Description =========== **osdmaptool** is a utility that lets you create, view, and manipulate OSD cluster maps from the Ceph distributed storage system. Notably, it lets you extract the embedded CRUSH map or import a new CRUSH map. It can also simulate the upmap balancer mode so you can get a sense of what is needed to balance your PGs. Options ======= .. option:: --print will simply make the tool print a plaintext dump of the map, after any modifications are made. .. option:: --dump displays the map in plain text when is 'plain', 'json' if specified format is not supported. This is an alternative to the print option. .. option:: --clobber will allow osdmaptool to overwrite mapfilename if changes are made. .. option:: --import-crush mapfile will load the CRUSH map from mapfile and embed it in the OSD map. .. option:: --export-crush mapfile will extract the CRUSH map from the OSD map and write it to mapfile. .. option:: --createsimple numosd [--pg-bits bitsperosd] [--pgp-bits bits] will create a relatively generic OSD map with the numosd devices. If --pg-bits is specified, the initial placement group counts will be set with bitsperosd bits per OSD. That is, the pg_num map attribute will be set to numosd shifted by bitsperosd. If --pgp-bits is specified, then the pgp_num map attribute will be set to numosd shifted by bits. .. option:: --create-from-conf creates an osd map with default configurations. .. option:: --test-map-pgs [--pool poolid] [--range-first --range-last ] will print out the mappings from placement groups to OSDs. If range is specified, then it iterates from first to last in the directory specified by argument to osdmaptool. Eg: **osdmaptool --test-map-pgs --range-first 0 --range-last 2 osdmap_dir**. This will iterate through the files named 0,1,2 in osdmap_dir. .. option:: --test-map-pgs-dump [--pool poolid] [--range-first --range-last ] will print out the summary of all placement groups and the mappings from them to the mapped OSDs. If range is specified, then it iterates from first to last in the directory specified by argument to osdmaptool. Eg: **osdmaptool --test-map-pgs-dump --range-first 0 --range-last 2 osdmap_dir**. This will iterate through the files named 0,1,2 in osdmap_dir. .. option:: --test-map-pgs-dump-all [--pool poolid] [--range-first --range-last ] will print out the summary of all placement groups and the mappings from them to all the OSDs. If range is specified, then it iterates from first to last in the directory specified by argument to osdmaptool. Eg: **osdmaptool --test-map-pgs-dump-all --range-first 0 --range-last 2 osdmap_dir**. This will iterate through the files named 0,1,2 in osdmap_dir. .. option:: --test-random does a random mapping of placement groups to the OSDs. .. option:: --test-map-pg map a particular placement group(specified by pgid) to the OSDs. .. option:: --test-map-object [--pool ] map a particular placement group(specified by objectname) to the OSDs. .. option:: --test-crush [--range-first --range-last ] map placement groups to acting OSDs. If range is specified, then it iterates from first to last in the directory specified by argument to osdmaptool. Eg: **osdmaptool --test-crush --range-first 0 --range-last 2 osdmap_dir**. This will iterate through the files named 0,1,2 in osdmap_dir. .. option:: --mark-up-in mark osds up and in (but do not persist). .. option:: --mark-out mark an osd as out (but do not persist) .. option:: --mark-up mark an osd as up (but do not persist) .. option:: --mark-in mark an osd as in (but do not persist) .. option:: --tree Displays a hierarchical tree of the map. .. option:: --clear-temp clears pg_temp and primary_temp variables. .. option:: --clean-temps clean pg_temps. .. option:: --health dump health checks .. option:: --with-default-pool include default pool when creating map .. option:: --upmap-cleanup clean up pg_upmap[_items] entries, writing commands to [default: - for stdout] .. option:: --upmap calculate pg upmap entries to balance pg layout writing commands to [default: - for stdout] .. option:: --upmap-max set max upmap entries to calculate [default: 10] .. option:: --upmap-deviation max deviation from target [default: 5] .. option:: --upmap-pool restrict upmap balancing to 1 pool or the option can be repeated for multiple pools .. option:: --upmap-active Act like an active balancer, keep applying changes until balanced .. option:: --adjust-crush-weight [,,<...>] Change CRUSH weight of .. option:: --save write modified osdmap with upmap or crush-adjust changes .. option:: --read calculate pg upmap entries to balance pg primaries .. option:: --read-pool specify which pool the read balancer should adjust .. option:: --vstart prefix upmap and read output with './bin/' Example ======= To create a simple map with 16 devices:: osdmaptool --createsimple 16 osdmap --clobber To view the result:: osdmaptool --print osdmap To view the mappings of placement groups for pool 1:: osdmaptool osdmap --test-map-pgs-dump --pool 1 pool 1 pg_num 8 1.0 [0,2,1] 0 1.1 [2,0,1] 2 1.2 [0,1,2] 0 1.3 [2,0,1] 2 1.4 [0,2,1] 0 1.5 [0,2,1] 0 1.6 [0,1,2] 0 1.7 [1,0,2] 1 #osd count first primary c wt wt osd.0 8 5 5 1 1 osd.1 8 1 1 1 1 osd.2 8 2 2 1 1 in 3 avg 8 stddev 0 (0x) (expected 2.3094 0.288675x)) min osd.0 8 max osd.0 8 size 0 0 size 1 0 size 2 0 size 3 8 In which, #. pool 1 has 8 placement groups. And two tables follow: #. A table for placement groups. Each row presents a placement group. With columns of: * placement group id, * acting set, and * primary OSD. #. A table for all OSDs. Each row presents an OSD. With columns of: * count of placement groups being mapped to this OSD, * count of placement groups where this OSD is the first one in their acting sets, * count of placement groups where this OSD is the primary of them, * the CRUSH weight of this OSD, and * the weight of this OSD. #. Looking at the number of placement groups held by 3 OSDs. We have * average, stddev, stddev/average, expected stddev, expected stddev / average * min and max #. The number of placement groups mapping to n OSDs. In this case, all 8 placement groups are mapping to 3 different OSDs. In a less-balanced cluster, we could have following output for the statistics of placement group distribution, whose standard deviation is 1.41421:: #osd count first primary c wt wt osd.0 8 5 5 1 1 osd.1 8 1 1 1 1 osd.2 8 2 2 1 1 #osd count first primary c wt wt osd.0 33 9 9 0.0145874 1 osd.1 34 14 14 0.0145874 1 osd.2 31 7 7 0.0145874 1 osd.3 31 13 13 0.0145874 1 osd.4 30 14 14 0.0145874 1 osd.5 33 7 7 0.0145874 1 in 6 avg 32 stddev 1.41421 (0.0441942x) (expected 5.16398 0.161374x)) min osd.4 30 max osd.1 34 size 00 size 10 size 20 size 364 To simulate the active balancer in upmap mode:: osdmaptool --upmap upmaps.out --upmap-active --upmap-deviation 6 --upmap-max 11 osdmap osdmaptool: osdmap file 'osdmap' writing upmap command output to: upmaps.out checking for upmap cleanups upmap, max-count 11, max deviation 6 pools movies photos metadata data prepared 11/11 changes Time elapsed 0.00310404 secs pools movies photos metadata data prepared 11/11 changes Time elapsed 0.00283402 secs pools data metadata movies photos prepared 11/11 changes Time elapsed 0.003122 secs pools photos metadata data movies prepared 11/11 changes Time elapsed 0.00324372 secs pools movies metadata data photos prepared 1/11 changes Time elapsed 0.00222609 secs pools data movies photos metadata prepared 0/11 changes Time elapsed 0.00209916 secs Unable to find further optimization, or distribution is already perfect osd.0 pgs 41 osd.1 pgs 42 osd.2 pgs 42 osd.3 pgs 41 osd.4 pgs 46 osd.5 pgs 39 osd.6 pgs 39 osd.7 pgs 43 osd.8 pgs 41 osd.9 pgs 46 osd.10 pgs 46 osd.11 pgs 46 osd.12 pgs 46 osd.13 pgs 41 osd.14 pgs 40 osd.15 pgs 40 osd.16 pgs 39 osd.17 pgs 46 osd.18 pgs 46 osd.19 pgs 39 osd.20 pgs 42 Total time elapsed 0.0167765 secs, 5 rounds To simulate the active balancer in read mode, first make sure capacity is balanced by running the balancer in upmap mode. Then, balance the reads on a replicated pool with:: osdmaptool osdmap --read read.out --read-pool ./bin/osdmaptool: osdmap file 'om' writing upmap command output to: read.out ---------- BEFORE ------------ osd.0 | primary affinity: 1 | number of prims: 3 osd.1 | primary affinity: 1 | number of prims: 10 osd.2 | primary affinity: 1 | number of prims: 3 read_balance_score of 'cephfs.a.meta': 1.88 ---------- AFTER ------------ osd.0 | primary affinity: 1 | number of prims: 5 osd.1 | primary affinity: 1 | number of prims: 5 osd.2 | primary affinity: 1 | number of prims: 6 read_balance_score of 'cephfs.a.meta': 1.13 num changes: 5 Availability ============ **osdmaptool** is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to the Ceph documentation at https://docs.ceph.com for more information. See also ======== :doc:`ceph `\(8), :doc:`crushtool `\(8),