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diff --git a/src/ceph/doc/man/8/osdmaptool.rst b/src/ceph/doc/man/8/osdmaptool.rst new file mode 100644 index 0000000..f58d29c --- /dev/null +++ b/src/ceph/doc/man/8/osdmaptool.rst @@ -0,0 +1,157 @@ +:orphan: + +====================================================== + osdmaptool -- ceph osd cluster map manipulation tool +====================================================== + +.. program:: osdmaptool + +Synopsis +======== + +| **osdmaptool** *mapfilename* [--print] [--createsimple *numosd* + [--pgbits *bitsperosd* ] ] [--clobber] + + +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. + + +Options +======= + +.. option:: --print + + will simply make the tool print a plaintext dump of the map, after + any modifications are made. + +.. 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 [--pgbits bitsperosd] + + will create a relatively generic OSD map with the numosd devices. + If --pgbits 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. + +.. option:: --test-map-pgs [--pool poolid] + + will print out the mappings from placement groups to OSDs. + +.. option:: --test-map-pgs-dump [--pool poolid] + + will print out the summary of all placement groups and the mappings + from them to the mapped OSDs. + + +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 0:: + + osdmaptool --test-map-pgs-dump rbd --pool 0 + + pool 0 pg_num 8 + 0.0 [0,2,1] 0 + 0.1 [2,0,1] 2 + 0.2 [0,1,2] 0 + 0.3 [2,0,1] 2 + 0.4 [0,2,1] 0 + 0.5 [0,2,1] 0 + 0.6 [0,1,2] 0 + 0.7 [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 0 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 + + * avarge, 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 + + +Availability +============ + +**osdmaptool** is part of Ceph, a massively scalable, open-source, distributed storage system. Please +refer to the Ceph documentation at http://ceph.com/docs for more +information. + + +See also +======== + +:doc:`ceph <ceph>`\(8), +:doc:`crushtool <crushtool>`\(8), |