man/rbd.8


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.TH RBD 8
.SH NAME
rbd \- manage rados block device (RBD) images
.SH SYNOPSIS
.B rbd
[ \fB\-c\fI ceph.conf\fR ]
[ \fB\-m\fI monaddr\fR ]
[ \fB\-p\fP | \fB\-\-pool\fI pool\fR ]
[ \fB\-\-size\fI size\fR ]
[ \fB\-\-order\fI bits\fR ]
[ \fIcommand ...\fR ]

.SH DESCRIPTION
.B rbd
is a utility for manipulating rados block device (RBD) images, used by the Linux
rbd driver and the rbd storage driver for Qemu/KVM.  RBD images are
simple block devices that are striped over objects and stored in a RADOS object store.
The size of the objects the image is striped over must be a power of two.
.SH OPTIONS
.TP
\fB\-c\fI ceph.conf\fR, \fB\-\-conf \fIceph.conf\fR
Use \fIceph.conf\fP configuration file instead of the default \fI/etc/ceph/ceph.conf\fP
to determine monitor addresses during startup.
.TP
\fB\-m\fI monaddress[:port]\fR
Connect to specified monitor (instead of looking through \fIceph.conf\fR).
.TP
\fB\-p\fI pool\fR, \fB\-\-pool \fIpool\fR
Interact with the given \fIpool\fP.  Required by most commands.
.SH PARAMETERS
.TP
\fB\-\-size \fIsize-in-mb\fP
Specifies the size (in megabytes) of the new rbd image.
.TP
\fB\-\-order \fIbits\fP
Specifies the object size expressed as a number of bits, such that the object size is 1 << \fIorder\fR. The default is 22 (4 MB).
.TP
\fB\-\-snap \fIsnap\fP
Specifies the snapshot name for the specific operation.
.TP
\fB\-\-user \fIusername\fP
Specifies the username to use with the map command.
.TP
\fB\-\-secret \fIfilename\fP
Specifies a file containing the secret to use with the map command.
.SH COMMANDS
.TP
\fBls \fR[ \fIpool-name\fP ]
Will list all rbd images listed in the \fIrbd_directory\fR object.
.TP
\fBinfo \fR[ \fIimage-name\fP ]
Will dump information (such as size and order) about a specific rbd image.
.TP
\fBcreate \fR[ \fIimage-name\fP ]
Will create a new rbd image.  You must also specify the size via \fB\-\-size\fR.
.TP
\fBresize \fR[ \fIimage-name\fP ]
Resizes rbd image.  The size parameter also needs to be specified.
.TP
\fBrm \fR[ \fIimage-name\fP ]
Deletes rbd image (including all data blocks)
.TP
\fBexport \fR[ \fIimage-name\fP ] \fR[ \fIdest-path\fP ]
Exports image to dest path.
.TP
\fBimport \fR[ \fIpath\fP ] \fR[ \fIdest-image\fP ]
Creates a new image and imports its data from path.
.TP
\fBcp \fR[ \fIsrc-image\fP ] \fR[ \fIdest-image\fP ]
Copies the content of a src-image into the newly created dest-image.
.TP
\fBmv \fR[ \fIsrc-image\fP ] \fR[ \fIdest-image\fP ]
Renames an image.
.TP
\fBsnap ls \fR[ \fIimage-name\fP ]
Dumps the list of snapshots inside a specific image.
.TP
\fBsnap create \fR[ \fIimage-name\fP ]
Creates a new snapshot. Requires the snapshot name parameter specified.
.TP
\fBsnap rollback \fR[ \fIimage-name\fP ]
Rollback image content to snapshot. This will iterate through the entire blocks array and update the data head content to the snapshotted version.
.TP
\fBsnap rm \fR[ \fIimage-name\fP ]
Removes the specified snapshot.
.TP
\fBmap \fR[ \fIimage-name\fP ]
Maps the specified image to a block device via the rbd kernel module.
.TP
\fBunmap \fR[ \fIdevice-path\fP ]
Unmaps the block device that was mapped via the rbd kernel module.
.SH IMAGE NAME
In addition to using the \fB\-\-pool\fR and the \fB\-\-snap\fR options, the image name can include both the pool name and the snapshot name. The image name format is as follows:
.IP
[\fIpool\fP/]image-name[@\fIsnap\fP]
.PP
Thus an image name that contains a slash character ('/') requires specifying the pool name explicitly.
.SH EXAMPLES
To create a new rbd image that is 100 GB:
.IP
rbd -p mypool create myimage --size 102400
.PP
or alternatively
.IP
rbd create mypool/myimage --size 102400
.PP
To use a non-default object size (8 MB):
.IP
rbd create mypool/myimage --size 102400 --order 23
.PP
To delete an rbd image (be careful!):
.IP
rbd rm mypool/myimage
.PP
To create a new snapshot:
.IP
rbd create mypool/myimage@mysnap
.PP
To map an image via the kernel with cephx enabled:
.IP
rbd map myimage --user admin --secret secretfile
.PP
To unmap an image:
.IP
rbd unmap /dev/rbd0
.PP
.SH AVAILABILITY
.B rbd
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), rados (8)