NAME

       drbdmeta - Manipulate the DRBD on-disk metadata

SYNOPSIS

       drbdmeta [--force] [--ignore-sanity-checks] {device} {v06 minor | v07 meta_dev index |
                v08 meta_dev index | v09 meta_dev index} {command} [cmd args...]

DESCRIPTION

       The drbdmeta utility is used for creating, displaying, and modifying DRBD's on-disk
       metadata. Users usually interact with the drbdadm utility, which provides a more
       high-level interface to DRBD than drbdmeta. (See drbdadm's --dry-run option to see how
       drbdadm uses drbdmeta.)

       This utility can only be used on devices which are not currently in use by the kernel.

       The first argument (device) specifies the drbd device associated with a volume, or “-” if
       no device is associated with that volume. If the drbd device is specified, the drbdmeta
       utility makes sure that the drbd device does not currently have a volume attached to
       prevent meta-data of an active volume from being destroyed.

       The second argument specifies the metadata version to use (v06, v07, v08, v09). In most
       metadata versions, the third argument (meta_dev) specifies the device which contains the
       metadata; this argument can be the same as device. The fourth argument (index) can be one
       of the keywords internal (for internal metadata), flex-internal (in v07 for variable-sized
       metadata; v07 otherwise defaults to fixed-size internal metadata), flex-external (for
       variable-sized external metadata), or a numeric matadata index (for fixed-size external
       metadata). See the meta-disk parameter in drbd.conf(5).

OPTIONS

       --force

           Assume yes as the answer to all questions drbdmeta would ask.

       --ignore-sanity-checks

           Normally, drbdmeta performs some sanity checks before writing to the metadata device:
           for example, if the device appears to contain a file system, it refuses to destroy the
           file system by writing into it. Use this option to ignore these checks.

COMMANDS

       create-md [--peer-max-bio-size=val] (metadata versions v06, v07, and v08),
       create-md {number-of-bitmap-slots} [--peer-max-bio-size=val]
       [--initialize-bitmap-mode={automatic|zeroout|pwrite|skip}] [--al-stripes=val]
       [--al-stripe-size-kB=val] (metadata version v09)

           Initialize the metadata. This is necessary before a DRBD resource can be attached. If
           drbdmeta finds an older version of DRBD metadata on the device, it asks if the format
           should be converted.

           When drbdadm calls drbdmeta's create-md command for a device, it sets the
           number-of-bitmap-slots argument to the number of peers in the resource. To reserve
           additional bitmap slots (which allows to add more peers in the future), call drbdmeta
           directly instead.

           When a device is used before being connected to its peers the first time, DRBD assumes
           that peers can only handle 4 KiB requests by default. The --peer-max-bio-size option
           allows to set more optimistic values; use this if the versions of DRBD that this
           device will connect to are known. DRBD supports a maximum bio size of 32 KiB since
           version 8.3.8, of 128 KiB since version 8.3.9, and of 1 MiB since version 8.4.0.

           By default, we explicitly initialize the bitmap area to all zero. With
           --initialize-bitmap-mode you can chose to only try the fast method (zeroout, try ioctl
           BLKZEROOUT only), only use explicit pwrite calls, or skip this bitmap initialization
           phase completely. If you intend to do an initial full sync anyways, you can use skip
           to leave the bitmap initialization to the kernel. This can make a noticable difference
           when initializing huge volumes. Default is automatic, which is zeroout with an
           implicit fallback to pwrite.

           If you want to use more than 6433 activity log extents, or live on top of a spriped
           RAID, you may specify the number of stripes (--al-stripes, default 1), and the stripe
           size (--al-stripe-size-kB, default 32). To just use a larger linear on-disk
           ring-buffer, leave the number of stripes at 1, and increase the size only:

           drbdmeta 0 v08 /dev/vg23/lv42 internal create-md --al-stripe-size 1M

           To avoid a single "spindle" from becoming a bottleneck, increase the number of
           stripes, to achieve an interleaved layout of the on-disk activity-log transactions.
           What you give as "stripe-size" should be what is a.k.a. "chunk size" or "granularity"
           or "strip unit": the minimum skip to the next "spindle".

           drbdmeta 0 v08 /dev/vg23/lv42 internal create-md --al-stripes 7 --al-stripe-size 64

       get-gi [--node-id=id]

           Show the data generation identifiers for a device on a particular connection. DRBD
           version 9.0.0 and beyond support multiple peers; use the node-id option to define
           which peer's data generation identifiers to show.

       show-gi [--node-id=id]

           Similar to get-gi, but with explanatory information.

       dump-md

           Dump the metadata of a device in text form, including the bitmap and activity log.

       outdate
           Mark the data on a lower-level device as outdated. See drbdsetup(8) for details.

       dstate
           Show the current disk state of a lower-level device.

       check-resize

           Examine the device size of a lower-level device and its last known device size (saved
           in /var/lib/drbd/drbd-minor-minor.lkbd by drbdsetup check-resize). For internal
           metadata, if the size of the lower-level device has changed and the metadata can be
           found at the previous position, move the metadata to the new position at the end of
           the block device.

       apply-al

           Apply the activity log of the specified device. This is necessary before the device
           can be attached by the kernel again.

EXPERT COMMANDS

       The drbdmeta utility can be used to fine tune metdata. Please note that this can lead to
       destroyed metadata or even silent data corruption; use with great care only.

       set-gi gi [--node-id=id]

           Set the generation identifiers. The gi argument is a generation counter for the v06
           and v07 formats, and a set of UUIDs for v08 and beyond. Accepts the same syntax as in
           the get-gi output. DRBD version 9.0.0 and beyond support multiple peers; use the
           --node-id option to define which peer's data generation identifiers to set.

       restore-md dump_file

           Replace the metadata on the device with the contents of dump_file. The dump file
           format is defined by the output of the dump-md command.

VERSION

       This document was revised for version 9.0.0 of the DRBD distribution.

AUTHOR

       Written by Philipp Reisner <philipp.reisner@linbit.com> and Lars Ellenberg
       <lars.ellenberg@linbit.com>.

REPORTING BUGS

       Report bugs to <drbd-user@lists.linbit.com>.

COPYRIGHT

       Copyright 2001-2008,2012 LINBIT Information Technologies, Philipp Reisner, Lars Ellenberg.
       This is free software; see the source for copying conditions. There is NO warranty; not
       even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

       drbdadm(8) drbd.conf(5)