drbdmeta - Manipulate the DRBD on-disk metadata
drbdmeta
[--force] [--ignore-sanity-checks] {
device} {v06
minor |
v07
meta_dev index |
v08
meta_dev index | v09
meta_dev index} {
command}
[
cmd args...]
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).
--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.
create-md [
--peer-max-bio-size=val] (metadata versions v06,
v07, and v08),
create-md {number-of-bitmap-slots}
[
--peer-max-bio-size=val] [
--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.
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.
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.
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.
This document was revised for version 9.0.0 of the DRBD distribution.
Written by Philipp Reisner <
[email protected]> and Lars Ellenberg
<
[email protected]>.
Report bugs to <
[email protected]>.
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.
drbdadm(8)
drbd.conf(5)
