osdmaptool – ceph osd cluster map manipulation tool¶

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¶

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

--clobber¶: 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.

Example¶

To create a simple map with 16 devices:

osdmaptool --createsimple 16 osdmap --clobber

To view the result:

osdmaptool --print osdmap

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.