Ubuntu Manpage: drbdmeta - DRBD's meta data management tool

NAME

       drbdmeta - DRBD's meta data management tool

SYNOPSIS

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

DESCRIPTION

       Drbdmeta is used to create, display and modify the contents of DRBD's meta data storage.
       Usually you do not want to use this command directly, but start it via the frontend
       drbdadm(8).

       This command only works if the DRBD resource is currently down, or at least detached from
       its backing storage. The first parameter is the device node associated to the resource.
       With the second parameter you can select the version of the meta data. Currently all major
       DRBD releases (0.6, 0.7 and 8) are supported.

OPTIONS

       --force

           All questions that get asked by drbdmeta are treated as if the user answered 'yes'.

       --ignore-sanity-checks

           Some sanity checks cause drbdmeta to terminate. E.g. if a file system image would get
           destroyed by creating the meta data. By using that option you can force drbdmeta to
           ignore these checks.

COMMANDS

create-md --peer-max-bio-size val --al-stripes val --al-stripe-size-kB val

Create-md initializes the meta data storage. This needs to be done before a DRBD
resource can be taken online for the first time. In case there is already a meta data
signature of an older format in place, drbdmeta will ask you if it should convert the
older format to the selected format.

If you will use the resource before it is connected to its peer for the first time
DRBD may perform better if you use the --peer-max-bio-size option. For DRBD versions
of the peer use up to these values: <8.3.7 -> 4k, 8.3.8 -> 32k, 8.3.9 -> 128k, 8.4.0
-> 1M.

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 64k

get-gi

Get-gi shows a short textual representation of the data generation identifier. In
version 0.6 and 0.7 these are generation counters, while in version 8 it is a set of
UUIDs.

show-gi

Show-gi prints a textual representation of the data generation identifiers including
explanatory information.

dump-md

Dumps the whole contents of the meta data storage including the stored bit-map and
activity-log in a textual representation.

outdate

Sets the outdated flag in the meta data. This is used by the peer node when it wants
to become primary, but cannot communicate with the DRBD stack on this host.

dstate

Prints the state of the data on the backing storage. The output is always followed by
'/DUnknown' since drbdmeta only looks at the local meta data.

check-resize

Examines the device size of a backing device, and it's last known device size,
recorded in a file /var/lib/drbd/drbd-minor-??.lkbd. In case the size of the backing
device changed, and the meta data can be found at the old position, it moves the meta
data to the right position at the end of the block device.

EXPERTS COMMANDS

       Drbdmeta allows you to modify the meta data as well. This is intentionally omitted for the
       command's usage output, since you should only use it if you really know what you are
       doing. By setting the generation identifiers to wrong values, you risk to overwrite your
       up-to-data data with an older version of your data.

       set-gi gi

           Set-gi allows you to set the generation identifier.  Gi needs to be a generation
           counter for the 0.6 and 0.7 format, and a UUID set for 8.x. Specify it in the same way
           as get-gi shows it.

       restore-md dump_file

           Reads the dump_file and writes it to the meta data.

VERSION

       This document was revised for version 8.3.2 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 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.