3 =========================================
4 rbdmap -- map RBD devices at boot time
5 =========================================
19 **rbdmap** is a shell script that automates ``rbd map`` and ``rbd unmap``
20 operations on one or more RBD (RADOS Block Device) images. While the script can be
21 run manually by the system administrator at any time, the principal use case is
22 automatic mapping/mounting of RBD images at boot time (and unmounting/unmapping
23 at shutdown), as triggered by the init system (a systemd unit file,
24 ``rbdmap.service`` is included with the ceph-common package for this purpose).
26 The script takes a single argument, which can be either "map" or "unmap".
27 In either case, the script parses a configuration file (defaults to ``/etc/ceph/rbdmap``,
28 but can be overridden via an environment variable ``RBDMAPFILE``). Each line
29 of the configuration file corresponds to an RBD image which is to be mapped, or
32 The configuration file format is::
36 where ``IMAGESPEC`` should be specified as ``POOLNAME/IMAGENAME`` (the pool
37 name, a forward slash, and the image name), or merely ``IMAGENAME``, in which
38 case the ``POOLNAME`` defaults to "rbd". ``RBDOPTS`` is an optional list of
39 parameters to be passed to the underlying ``rbd map`` command. These parameters
40 and their values should be specified as a comma-separated string::
42 PARAM1=VAL1,PARAM2=VAL2,...,PARAMN=VALN
44 This will cause the script to issue an ``rbd map`` command like the following::
46 rbd map POOLNAME/IMAGENAME --PARAM1 VAL1 --PARAM2 VAL2
48 (See the ``rbd`` manpage for a full list of possible options.)
50 When run as ``rbdmap map``, the script parses the configuration file, and for
51 each RBD image specified attempts to first map the image (using the ``rbd map``
52 command) and, second, to mount the image.
54 When run as ``rbdmap unmap``, images listed in the configuration file will
55 be unmounted and unmapped.
57 ``rbdmap unmap-all`` attempts to unmount and subsequently unmap all currently
58 mapped RBD images, regardless of whether or not they are listed in the
61 If successful, the ``rbd map`` operation maps the image to a ``/dev/rbdX``
62 device, at which point a udev rule is triggered to create a friendly device
63 name symlink, ``/dev/rbd/POOLNAME/IMAGENAME``, pointing to the real mapped
66 In order for mounting/unmounting to succeed, the friendly device name must
67 have a corresponding entry in ``/etc/fstab``.
69 When writing ``/etc/fstab`` entries for RBD images, it's a good idea to specify
70 the "noauto" (or "nofail") mount option. This prevents the init system from
71 trying to mount the device too early - before the device in question even
72 exists. (Since ``rbdmap.service``
73 executes a shell script, it is typically triggered quite late in the boot
80 Example ``/etc/ceph/rbdmap`` for two RBD images called "bar1" and "bar2", both
83 foopool/bar1 id=admin,keyring=/etc/ceph/ceph.client.admin.keyring
84 foopool/bar2 id=admin,keyring=/etc/ceph/ceph.client.admin.keyring
86 Each line in the file contains two strings: the image spec and the options to
87 be passed to ``rbd map``. These two lines get transformed into the following
90 rbd map foopool/bar1 --id admin --keyring /etc/ceph/ceph.client.admin.keyring
91 rbd map foopool/bar2 --id admin --keyring /etc/ceph/ceph.client.admin.keyring
93 If the images had XFS filesystems on them, the corresponding ``/etc/fstab``
94 entries might look like this::
96 /dev/rbd/foopool/bar1 /mnt/bar1 xfs noauto 0 0
97 /dev/rbd/foopool/bar2 /mnt/bar2 xfs noauto 0 0
99 After creating the images and populating the ``/etc/ceph/rbdmap`` file, making
100 the images get automatically mapped and mounted at boot is just a matter of
103 systemctl enable rbdmap.service
115 **rbdmap** is part of Ceph, a massively scalable, open-source, distributed
116 storage system. Please refer to the Ceph documentation at
117 http://ceph.com/docs for more information.
123 :doc:`rbd <rbd>`\(8),