DRBDMETA(8) System Administration DRBDMETA(8)NAMEdrbdmeta - DRBD's meta data management tool .
SYNOPSISdrbdmeta [--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.
EXPERT'S 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.
SEE ALSOdrbdadm(8)DRBD 8.3.2 15 Oct 2008 DRBDMETA(8)
