.TH OSDMAPTOOL 8
.SH NAME
osdmaptool \- ceph osd cluster map manipulation tool
.SH SYNOPSIS
.B osdmaptool
\fImapfilename\fP
[\fB\-\-print\fR]
[\fB\-\-createsimple \fInumosd\fR [\fB\-\-pgbits \fIbitsperosd\fR]]
[\fB\-\-clobber\fR]
.SH DESCRIPTION
.B osdmaptool
is a utility that lets you create, view, and manipulate OSD cluster maps from the
Ceph distributed file system.  Notably, it lets you extract the embedded CRUSH map
or import a new CRUSH map.
.SH OPTIONS
.TP
\fB\-\-print\fP
will simply make the tool print a plaintext dump of the map, after any modifications are made.
.TP
\fB\-\-clobber\fP
will allow
.B osdmaptool
to overwrite \fImapfilename\fP if changes are made.
.TP
\fB\-\-import-crush\fI mapfile\fP
will load the CRUSH map from \fImapfile\fP and embed it in the OSD map.
.TP
\fB\-\-export-crush\fI mapfile\fP
will extract the CRUSH map from the OSD map and write it to \fImapfile\fP.
.TP
\fB\-\-createsimple\fI numosd\fP [\fB\-\-pgbits \fIbitsperosd\fR]
will create a relatively generic OSD map with the \fInumosd\fP devices.  If \fB\-\-pgbits\fP 
is specified, the initial placement group counts will be set with \fIbitsperosd\fP bits per OSD.
That is, the \fIpg_num\fP map attribute will be set to \fInumosd\fP shifted by \fIbitsperosd\fP.
.SH EXAMPLE
To create a simple map with 16 devices:
.IP
osdmaptool --createsimple 16 osdmap --clobber
.PP
To view the result:
.IP
osdmaptool --print osdmap
.SH AVAILABILITY
.B osdmaptool
is part of the Ceph distributed file system.  Please refer to the Ceph wiki at
http://ceph.newdream.net/wiki for more information.
.SH SEE ALSO
.BR ceph (8),
.BR crushtool (8),
.BR mkcephfs (8)