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osdmaptool - ceph osd cluster map manipulation tool



osdmaptool - ceph osd cluster map manipulation tool


osdmaptool mapfilename [--print] [--createsimple numosd
[--pgbits  bitsperosd ] ] [--clobber]


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.


will simply make the tool print a plaintext dump of the map, after any modifications are made.

will allow osdmaptool to overwrite mapfilename if changes are made.

--import-crush mapfile
will load the CRUSH map from mapfile and embed it in the OSD map.

--export-crush mapfile
will extract the CRUSH map from the OSD map and write it to mapfile.

--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.


To create a simple map with 16 devices:
osdmaptool --createsimple 16 osdmap --clobber

To view the result:
osdmaptool --print osdmap


osdmaptool is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to the Ceph documentation at for more information.


ceph(8), crushtool(8), 2010-2017, Inktank Storage, Inc. and contributors. Licensed under Creative Commons BY-SA
June 7, 2017 dev