NAME
drbdsetup - Setup tool for DRBD .
SYNOPSIS
drbdsetup {device} disk {lower_dev} {meta_data_dev} {meta_data_index}
[-d {size}] [-e {err_handler}] [-f {fencing_policy}] [-b]
drbdsetup {device} net [af:] {local_addr} [:port] [af:] {remote_addr}
[:port] {protocol} [-c {time}] [-i {time}] [-t {val}]
[-S {size}] [-r {size}] [-k {count}] [-e {max_epoch_size}]
[-b {max_buffers}] [-m] [-a {hash_alg}] [-x {shared_secret}]
[-A {asb-0p-policy}] [-B {asb-1p-policy}]
[-C {asb-2p-policy}] [-D] [-R {role-resync-conflict-policy}]
[-p {ping_timeout}] [-u {val}] [-d {hash_alg}] [-o] [-n]
drbdsetup {device} syncer [-a {dev_minor}] [-r {rate}] [-e {extents}]
[-v {verify-hash-alg}] [-c {cpu-mask}] [-C {csums-hash-alg}]
[-R] [-V {delay-probe-volume}] [-I {delay-probe-interval}]
[-T {throttle-delay}] [-H {hold-off-delay}]
drbdsetup {device} disconnect
drbdsetup {device} detach
drbdsetup {device} down
drbdsetup {device} primary [-f] [-o]
drbdsetup {device} secondary
drbdsetup {device} verify [-s {start-position}]
drbdsetup {device} invalidate
drbdsetup {device} invalidate-remote
drbdsetup {device} wait-connect [-t {wfc_timeout}]
[-d {degr_wfc_timeout}] [-o {outdated_wfc_timeout}] [-w]
drbdsetup {device} wait-sync [-t {wfc_timeout}] [-d {degr_wfc_timeout}]
[-o {outdated_wfc_timeout}] [-w]
drbdsetup {device} role
drbdsetup {device} cstate
drbdsetup {device} dstate
drbdsetup {device} status
drbdsetup {device} resize [-d {size}] [-f {assume-peer-has-space}]
[-c {assume-clean}]
drbdsetup {device} check-resize
drbdsetup {device} pause-sync
drbdsetup {device} resume-sync
drbdsetup {device} outdate
drbdsetup {device} show-gi
drbdsetup {device} get-gi
drbdsetup {device} show
drbdsetup {device} suspend-io
drbdsetup {device} resume-io
drbdsetup {device} events [-u] [-a]
drbdsetup {device} new-current-uuid [-c]
DESCRIPTION
drbdsetup is used to associate DRBD devices with their backing block
devices, to set up DRBD device pairs to mirror their backing block
devices, and to inspect the configuration of running DRBD devices.
NOTE
drbdsetup is a low level tool of the DRBD program suite. It is used by
the data disk and drbd scripts to communicate with the device driver.
COMMANDS
Each drbdsetup sub-command might require arguments and bring its own
set of options. All values have default units which might be overruled
by K, M or G. These units are defined in the usual way (e.g. K = 2^10 =
1024).
Common options
All drbdsetup sub-commands accept these two options
--create-device
In case the specified DRBD device (minor number) does not exist
yet, create it implicitly.
--set-defaults
When --set-defaults is given on the command line, all options of
the invoked sub-command that are not explicitly set are reset to
their default values.
disk
Associates device with lower_device to store its data blocks on. The -d
(or --disk-size) should only be used if you wish not to use as much as
possible from the backing block devices. If you do not use -d, the
device is only ready for use as soon as it was connected to its peer
once. (See the net command.)
-d, --disk-size size
You can override DRBD's size determination method with this option.
If you need to use the device before it was ever connected to its
peer, use this option to pass the size of the DRBD device to the
driver. Default unit is sectors (1s = 512 bytes).
If you use the size parameter in drbd.conf, we strongly recommend
to add an explicit unit postfix. drbdadm and drbdsetup used to have
mismatching default units.
-e, --on-io-error err_handler
If the driver of the lower_device reports an error to DRBD, DRBD
will either pass the error to the upper layers of the operating
system, call a helper program, or detach the device from its
backing storage and perform all further IO by requesting it from
the peer. The valid err_handlers are: pass_on, call-local-io-error
and detach.
-f, --fencing fencing_policy
Under fencing we understand preventive measures to avoid situations
where both nodes are primary and disconnected (AKA split brain).
Valid fencing policies are:
dont-care
This is the default policy. No fencing actions are done.
resource-only
If a node becomes a disconnected primary, it tries to outdate
the peer's disk. This is done by calling the fence-peer
handler. The handler is supposed to reach the other node over
alternative communication paths and call 'drbdadm outdate res'
there.
resource-and-stonith
If a node becomes a disconnected primary, it freezes all its IO
operations and calls its fence-peer handler. The fence-peer
handler is supposed to reach the peer over alternative
communication paths and call 'drbdadm outdate res' there. In
case it cannot reach the peer, it should stonith the peer. IO
is resumed as soon as the situation is resolved. In case your
handler fails, you can resume IO with the resume-io command.
-b, --use-bmbv
In case the backing storage's driver has a merge_bvec_fn()
function, DRBD has to pretend that it can only process IO requests
in units not larger than 4 KiB. (At time of writing the only known
drivers which have such a function are: md (software raid driver),
dm (device mapper - LVM) and DRBD itself)
To get best performance out of DRBD on top of software raid (or any
other driver with a merge_bvec_fn() function) you might enable this
option, if you know for sure that the merge_bvec_fn() function will
deliver the same results on all nodes of your cluster. I.e. the
physical disks of the software raid are exactly of the same type.
USE THIS OPTION ONLY IF YOU KNOW WHAT YOU ARE DOING.
-a, --no-disk-barrier, -i, --no-disk-flushes, -D, --no-disk-drain
DRBD has four implementations to express write-after-write
dependencies to its backing storage device. DRBD will use the first
method that is supported by the backing storage device and that is
not disabled by the user.
When selecting the method you should not only base your decision on
the measurable performance. In case your backing storage device has
a volatile write cache (plain disks, RAID of plain disks) you
should use one of the first two. In case your backing storage
device has battery-backed write cache you may go with option 3 or
4. Option 4 will deliver the best performance such devices.
Unfortunately device mapper (LVM) might not support barriers.
The letter after "wo:" in /proc/drbd indicates with method is
currently in use for a device: b, f, d, n. The implementations:
barrier
The first requires that the driver of the backing storage
device support barriers (called 'tagged command queuing' in
SCSI and 'native command queuing' in SATA speak). The use of
this method can be disabled by the --no-disk-barrier option.
flush
The second requires that the backing device support disk
flushes (called 'force unit access' in the drive vendors
speak). The use of this method can be disabled using the
--no-disk-flushes option.
drain
The third method is simply to let write requests drain before
write requests of a new reordering domain are issued. That was
the only implementation before 8.0.9. You can prevent to use of
this method by using the --no-disk-drain option.
none
The fourth method is to not express write-after-write
dependencies to the backing store at all.
-m, --no-md-flushes
Disables the use of disk flushes and barrier BIOs when accessing
the meta data device. See the notes on --no-disk-flushes.
-s, --max-bio-bvecs
In some special circumstances the device mapper stack manages to
pass BIOs to DRBD that violate the constraints that are set forth
by DRBD's merge_bvec() function and which have more than one bvec.
A known example is: phys-disk -> DRBD -> LVM -> Xen -> missaligned
partition (63) -> DomU FS. Then you might see "bio would need to,
but cannot, be split:" in the Dom0's kernel log.
The best workaround is to proper align the partition within the VM
(E.g. start it at sector 1024). That costs 480 KiB of storage.
Unfortunately the default of most Linux partitioning tools is to
start the first partition at an odd number (63). Therefore most
distributions install helpers for virtual linux machines will end
up with missaligned partitions. The second best workaround is to
limit DRBD's max bvecs per BIO (i.e., the max-bio-bvecs option) to
1, but that might cost performance.
The default value of max-bio-bvecs is 0, which means that there is
no user imposed limitation.
net
Sets up the device to listen on af:local_addr:port for incoming
connections and to try to connect to af:remote_addr:port. If port is
omitted, 7788 is used as default. If af is omitted ipv4 gets used.
Other supported address families are ipv6, ssocks for Dolphin
Interconnect Solutions' "super sockets" and sdp for Sockets Direct
Protocol (Infiniband).
On the TCP/IP link the specified protocol is used. Valid protocol
specifiers are A, B, and C.
Protocol A: write IO is reported as completed, if it has reached local
disk and local TCP send buffer.
Protocol B: write IO is reported as completed, if it has reached local
disk and remote buffer cache.
Protocol C: write IO is reported as completed, if it has reached both
local and remote disk.
-c, --connect-int time
In case it is not possible to connect to the remote DRBD device
immediately, DRBD keeps on trying to connect. With this option you
can set the time between two retries. The default value is 10
seconds, the unit is 1 second.
-i, --ping-int time
If the TCP/IP connection linking a DRBD device pair is idle for
more than time seconds, DRBD will generate a keep-alive packet to
check if its partner is still alive. The default value is 10
seconds, the unit is 1 second.
-t, --timeout val
If the partner node fails to send an expected response packet
within val tenths of a second, the partner node is considered dead
and therefore the TCP/IP connection is abandoned. The default value
is 60 (= 6 seconds).
-S, --sndbuf-size size
The socket send buffer is used to store packets sent to the
secondary node, which are not yet acknowledged (from a network
point of view) by the secondary node. When using protocol A, it
might be necessary to increase the size of this data structure in
order to increase asynchronicity between primary and secondary
nodes. But keep in mind that more asynchronicity is synonymous with
more data loss in the case of a primary node failure. Since 8.0.13
resp. 8.2.7 setting the size value to 0 means that the kernel
should autotune this. The default size is 0, i.e. autotune.
-r, --rcvbuf-size size
Packets received from the network are stored in the socket receive
buffer first. From there they are consumed by DRBD. Before 8.3.2
the receive buffer's size was always set to the size of the socket
send buffer. Since 8.3.2 they can be tuned independently. A value
of 0 means that the kernel should autotune this. The default size
is 0, i.e. autotune.
-k, --ko-count count
In case the secondary node fails to complete a single write request
for count times the timeout, it is expelled from the cluster, i.e.
the primary node goes into StandAlone mode. The default is 0, which
disables this feature.
-e, --max-epoch-size val
With this option the maximal number of write requests between two
barriers is limited. Should be set to the same as --max-buffers.
Values smaller than 10 can lead to degraded performance. The
default value is 2048.
-b, --max-buffers val
With this option the maximal number of buffer pages allocated by
DRBD's receiver thread is limited. Should be set to the same as
--max-epoch-size. Small values could lead to degraded performance.
The default value is 2048, the minimum 32.
-u, --unplug-watermark val
When the number of pending write requests on the standby
(secondary) node exceeds the unplug-watermark, we trigger the
request processing of our backing storage device. Some storage
controllers deliver better performance with small values, others
deliver best performance when the value is set to the same value as
max-buffers. Minimum 16, default 128, maximum 131072.
-m, --allow-two-primaries
With this option set you may assign primary role to both nodes. You
only should use this option if you use a shared storage file system
on top of DRBD. At the time of writing the only ones are: OCFS2 and
GFS. If you use this option with any other file system, you are
going to crash your nodes and to corrupt your data!
-a, --cram-hmac-alg alg
You need to specify the HMAC algorithm to enable peer
authentication at all. You are strongly encouraged to use peer
authentication. The HMAC algorithm will be used for the challenge
response authentication of the peer. You may specify any digest
algorithm that is named in /proc/crypto.
-x, --shared-secret secret
The shared secret used in peer authentication. May be up to 64
characters.
-A, --after-sb-0pri asb-0p-policy
possible policies are:
disconnect
No automatic resynchronization, simply disconnect.
discard-younger-primary
Auto sync from the node that was primary before the split-brain
situation occurred.
discard-older-primary
Auto sync from the node that became primary as second during
the split-brain situation.
discard-zero-changes
In case one node did not write anything since the split brain
became evident, sync from the node that wrote something to the
node that did not write anything. In case none wrote anything
this policy uses a random decision to perform a "resync" of 0
blocks. In case both have written something this policy
disconnects the nodes.
discard-least-changes
Auto sync from the node that touched more blocks during the
split brain situation.
discard-node-NODENAME
Auto sync to the named node.
-B, --after-sb-1pri asb-1p-policy
possible policies are:
disconnect
No automatic resynchronization, simply disconnect.
consensus
Discard the version of the secondary if the outcome of the
after-sb-0pri algorithm would also destroy the current
secondary's data. Otherwise disconnect.
discard-secondary
Discard the secondary's version.
call-pri-lost-after-sb
Always honor the outcome of the after-sb-0pri algorithm. In
case it decides the current secondary has the correct data,
call the pri-lost-after-sb on the current primary.
violently-as0p
Always honor the outcome of the after-sb-0pri algorithm. In
case it decides the current secondary has the correct data,
accept a possible instantaneous change of the primary's data.
-C, --after-sb-2pri asb-2p-policy
possible policies are:
disconnect
No automatic resynchronization, simply disconnect.
call-pri-lost-after-sb
Always honor the outcome of the after-sb-0pri algorithm. In
case it decides the current secondary has the right data, call
the pri-lost-after-sb on the current primary.
violently-as0p
Always honor the outcome of the after-sb-0pri algorithm. In
case it decides the current secondary has the right data,
accept a possible instantaneous change of the primary's data.
-P, --always-asbp
Normally the automatic after-split-brain policies are only used if
current states of the UUIDs do not indicate the presence of a third
node.
With this option you request that the automatic after-split-brain
policies are used as long as the data sets of the nodes are somehow
related. This might cause a full sync, if the UUIDs indicate the
presence of a third node. (Or double faults have led to strange
UUID sets.)
-R, --rr-conflict role-resync-conflict-policy
This option sets DRBD's behavior when DRBD deduces from its meta
data that a resynchronization is needed, and the SyncTarget node is
already primary. The possible settings are: disconnect,
call-pri-lost and violently. While disconnect speaks for itself,
with the call-pri-lost setting the pri-lost handler is called which
is expected to either change the role of the node to secondary, or
remove the node from the cluster. The default is disconnect.
With the violently setting you allow DRBD to force a primary node
into SyncTarget state. This means that the data exposed by DRBD
changes to the SyncSource's version of the data instantaneously.
USE THIS OPTION ONLY IF YOU KNOW WHAT YOU ARE DOING.
-d, --data-integrity-alg hash_alg
DRBD can ensure the data integrity of the user's data on the
network by comparing hash values. Normally this is ensured by the
16 bit checksums in the headers of TCP/IP packets. This option can
be set to any of the kernel's data digest algorithms. In a typical
kernel configuration you should have at least one of md5, sha1, and
crc32c available. By default this is not enabled.
See also the notes on data integrity on the drbd.conf manpage.
-o, --no-tcp-cork
DRBD usually uses the TCP socket option TCP_CORK to hint to the
network stack when it can expect more data, and when it should
flush out what it has in its send queue. There is at least one
network stack that performs worse when one uses this hinting
method. Therefore we introduced this option, which disable the
setting and clearing of the TCP_CORK socket option by DRBD.
-p, --ping-timeout ping_timeout
The time the peer has to answer to a keep-alive packet. In case the
peer's reply is not received within this time period, it is
considered dead. The default unit is tenths of a second, the
default value is 5 (for half a second).
-D, --discard-my-data
Use this option to manually recover from a split-brain situation.
In case you do not have any automatic after-split-brain policies
selected, the nodes refuse to connect. By passing this option you
make this node a sync target immediately after successful connect.
-n, --dry-run
Causes DRBD to abort the connection process after the resync
handshake, i.e. no resync gets performed. You can find out which
resync DRBD would perform by looking at the kernel's log file.
syncer
Changes the synchronization daemon parameters of device at runtime.
-r, --rate rate
To ensure smooth operation of the application on top of DRBD, it is
possible to limit the bandwidth that may be used by background
synchronization. The default is 250 KiB/sec, the default unit is
KiB/sec.
-a, --after minor
Start resync on this device only if the device with minor is
already in connected state. Otherwise this device waits in
SyncPause state.
-e, --al-extents extents
DRBD automatically performs hot area detection. With this parameter
you control how big the hot area (=active set) can get. Each extent
marks 4M of the backing storage. In case a primary node leaves the
cluster unexpectedly, the areas covered by the active set must be
resynced upon rejoining of the failed node. The data structure is
stored in the meta-data area, therefore each change of the active
set is a write operation to the meta-data device. A higher number
of extents gives longer resync times but less updates to the
meta-data. The default number of extents is 127. (Minimum: 7,
Maximum: 3843)
-v, --verify-alg hash-alg
During online verification (as initiated by the verify
sub-command), rather than doing a bit-wise comparison, DRBD applies
a hash function to the contents of every block being verified, and
compares that hash with the peer. This option defines the hash
algorithm being used for that purpose. It can be set to any of the
kernel's data digest algorithms. In a typical kernel configuration
you should have at least one of md5, sha1, and crc32c available. By
default this is not enabled; you must set this option explicitly in
order to be able to use on-line device verification.
See also the notes on data integrity on the drbd.conf manpage.
-c, --cpu-mask cpu-mask
Sets the cpu-affinity-mask for DRBD's kernel threads of this
device. The default value of cpu-mask is 0, which means that DRBD's
kernel threads should be spread over all CPUs of the machine. This
value must be given in hexadecimal notation. If it is too big it
will be truncated.
-C, --csums-alg hash-alg
A resync process sends all marked data blocks form the source to
the destination node, as long as no csums-alg is given. When one is
specified the resync process exchanges hash values of all marked
blocks first, and sends only those data blocks over, that have
different hash values.
This setting is useful for DRBD setups with low bandwidth links.
During the restart of a crashed primary node, all blocks covered by
the activity log are marked for resync. But a large part of those
will actually be still in sync, therefore using csums-alg will
lower the required bandwidth in exchange for CPU cycles.
-R, --use-rle
During resync-handshake, the dirty-bitmaps of the nodes are
exchanged and merged (using bit-or), so the nodes will have the
same understanding of which blocks are dirty. On large devices, the
fine grained dirty-bitmap can become large as well, and the bitmap
exchange can take quite some time on low-bandwidth links.
Because the bitmap typically contains compact areas where all bits
are unset (clean) or set (dirty), a simple run-length encoding
scheme can considerably reduce the network traffic necessary for
the bitmap exchange.
For backward compatibilty reasons, and because on fast links this
possibly does not improve transfer time but consumes cpu cycles,
this defaults to off.
Introduced in 8.3.2.
-V, --delay-probe-volume volume, -I, --delay-probe-interval interval,
-T, --throttle-threshold throttle_delay, -H, --hold-off-threshold
hold_off_delay
During resync at least every volume bytes of data and at least
every interval * 100ms a pair of delay probes get inserted in
DRBD's packet stream. Those packets are used to measure the delay
of packts on the data socket caused by queuing in various network
components along the path.
If the delay on the data socket becomes greater than throttle_delay
DRBD will slow down the resync in order to keep the delay small.
The resync speed gets linearly slowed down it reaches 0 at a delay
of hold_off_delay.
The default value of volume is 16384 (16 MiB), the default unit is
KiB. Interval has 5 (500ms), throttle_delay 20 (2 seconds),
hold_off_delay 100 (10 seconds) as default value. The default unit
of the latter three is 100ms.
primary
Sets the device into primary role. This means that applications (e.g. a
file system) may open the device for read and write access. Data
written to the device in primary role are mirrored to the device in
secondary role.
Normally it is not possible to set both devices of a connected DRBD
device pair to primary role. By using the --allow-two-primaries option,
you override this behavior and instruct DRBD to allow two primaries.
-o, --overwrite-data-of-peer
Alias for --force.
-f, --force
Becoming primary fails if the local replica is not up-to-date. I.e.
when it is inconsistent, outdated of consistent. By using this
option you can force it into primary role anyway. USE THIS OPTION
ONLY IF YOU KNOW WHAT YOU ARE DOING.
secondary
Brings the device into secondary role. This operation fails as long as
at least one application (or file system) has opened the device.
It is possible that both devices of a connected DRBD device pair are
secondary.
verify
This initiates on-line device verification. During on-line
verification, the contents of every block on the local node are
compared to those on the peer node. Device verification progress can be
monitored via /proc/drbd. Any blocks whose content differs from that of
the corresponding block on the peer node will be marked out-of-sync in
DRBD's on-disk bitmap; they are not brought back in sync automatically.
To do that, simply disconnect and reconnect the resource.
If on-line verification is already in progress, this command silently
does nothing.
This command will fail if the device is not part of a connected device
pair.
See also the notes on data integrity on the drbd.conf manpage.
-s, --start start-sector
Since version 8.3.2, on-line verification should resume from the
last position after connection loss. It may also be started from an
arbitrary position by setting this option.
Default unit is sectors. You may also specify a unit explicitly.
The start-sector will be rounded down to a multiple of 8 sectors
(4kB).
invalidate
This forces the local device of a pair of connected DRBD devices into
SyncTarget state, which means that all data blocks of the device are
copied over from the peer.
This command will fail if the device is not part of a connected device
pair.
invalidate-remote
This forces the local device of a pair of connected DRBD devices into
SyncSource state, which means that all data blocks of the device are
copied to the peer.
wait-connect
Returns as soon as the device can communicate with its partner device.
-t, --wfc-timeout wfc_timeout, -d, --degr-wfc-timeout degr_wfc_timeout,
-o, --outdated-wfc-timeout outdated_wfc_timeout, -w, --wait-after-sb
This command will fail if the device cannot communicate with its
partner for timeout seconds. If the peer was working before this
node was rebooted, the wfc_timeout is used. If the peer was already
down before this node was rebooted, the degr_wfc_timeout is used.
If the peer was sucessfully outdated before this node was rebooted
the outdated_wfc_timeout is used. The default value for all those
timeout values is 0 which means to wait forever. In case the
connection status goes down to StandAlone because the peer appeared
but the devices had a split brain situation, the default for the
command is to terminate. You can change this behavior with the
--wait-after-sb option.
wait-sync
Returns as soon as the device leaves any synchronization into connected
state. The options are the same as with the wait-connect command.
disconnect
Removes the information set by the net command from the device. This
means that the device goes into unconnected state and will no longer
listen for incoming connections.
detach
Removes the information set by the disk command from the device. This
means that the device is detached from its backing storage device.
down
Removes all configuration information from the device and forces it
back to unconfigured state.
role
Shows the current roles of the device and its peer, as local/peer.
state
Deprecated alias for "role"
cstate
Shows the current connection state of the device.
dstate
Shows the current states of the backing storage devices, as local/peer.
status
Shows the current status of the device in XML-like format. Example
output:
<resource minor="0" name="s0" cs="SyncTarget" st1="Secondary" st2="Secondary"
ds1="Inconsistent" ds2="UpToDate" resynced_precent="5.9" />
resize
This causes DRBD to reexamine the size of the device's backing storage
device. To actually do online growing you need to extend the backing
storages on both devices and call the resize command on one of your
nodes.
The --assume-peer-has-space allows you to resize a device which is
currently not connected to the peer. Use with care, since if you do not
resize the peer's disk as well, further connect attempts of the two
will fail.
When the --assume-clean option is given DRBD will skip the resync of
the new storage. Only do this if you know that the new storage was
initialized to the same content by other means.
check-resize
To enable DRBD to detect offline resizing of backing devices this
command may be used to record the current size of backing devices. The
size is stored in files in /var/lib/drbd/ named drbd-minor-??.lkbd
This command is called by drbdadm resize res after drbdsetup device
resize returned.
pause-sync
Temporarily suspend an ongoing resynchronization by setting the local
pause flag. Resync only progresses if neither the local nor the remote
pause flag is set. It might be desirable to postpone DRBD's
resynchronization after eventual resynchronization of the backing
storage's RAID setup.
resume-sync
Unset the local sync pause flag.
outdate
Mark the data on the local backing storage as outdated. An outdated
device refuses to become primary. This is used in conjunction with
fencing and by the peer's fence-peer handler.
show-gi
Displays the device's data generation identifiers verbosely.
get-gi
Displays the device's data generation identifiers.
show
Shows all available configuration information of the device.
suspend-io
This command is of no apparent use and just provided for the sake of
completeness.
resume-io
If the fence-peer handler fails to stonith the peer node, and your
fencing policy is set to resource-and-stonith, you can unfreeze IO
operations with this command.
events
Displays every state change of DRBD and all calls to helper programs.
This might be used to get notified of DRBD's state changes by piping
the output to another program.
-a, --all-devices
Display the events of all DRBD minors.
-u, --unfiltered
This is a debugging aid that displays the content of all received
netlink messages.
new-current-uuid
Generates a new current UUID and rotates all other UUID values. This
has at least two use cases, namely to skip the initial sync, and to
reduce network bandwidth when starting in a single node configuration
and then later (re-)integrating a remote site.
Available option:
-c, --clear-bitmap
Clears the sync bitmap in addition to generating a new current
UUID.
This can be used to skip the initial sync, if you want to start from
scratch. This use-case does only work on "Just Created" meta data.
Necessary steps:
1. On both nodes, initialize meta data and configure the device.
drbdadm -- --force create-md res
2. They need to do the initial handshake, so they know their sizes.
drbdadm up res
3. They are now Connected Secondary/Secondary
Inconsistent/Inconsistent. Generate a new current-uuid and clear
the dirty bitmap.
drbdadm -- --clear-bitmap new-current-uuid res
4. They are now Connected Secondary/Secondary UpToDate/UpToDate. Make
one side primary and create a file system.
drbdadm primary res
mkfs -t fs-type $(drbdadm sh-dev res)
One obvious side-effect is that the replica is full of old garbage
(unless you made them identical using other means), so any
online-verify is expected to find any number of out-of-sync blocks.
You must not use this on pre-existing data! Even though it may appear
to work at first glance, once you switch to the other node, your data
is toast, as it never got replicated. So do not leave out the mkfs (or
equivalent).
This can also be used to shorten the initial resync of a cluster where
the second node is added after the first node is gone into production,
by means of disk shipping. This use-case works on disconnected devices
only, the device may be in primary or secondary role.
The necessary steps on the current active server are:
1. drbdsetup device new-current-uuid --clear-bitmap
2. Take the copy of the current active server. E.g. by pulling a disk
out of the RAID1 controller, or by copying with dd. You need to
copy the actual data, and the meta data.
3. drbdsetup device new-current-uuid
Now add the disk to the new secondary node, and join it to the cluster.
You will get a resync of that parts that were changed since the first
call to drbdsetup in step 1.
EXAMPLES
For examples, please have a look at the DRBD User's Guide[1].
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 ALSO
drbd.conf(5), drbd(8), drbddisk(8), drbdadm(8), DRBD User's Guide[1],
DRBD web site[2]
NOTES
1. DRBD User's Guide
http://www.drbd.org/users-guide/
2. DRBD web site
http://www.drbd.org/