other versions
- wheezy-backports 8.9.2~rc1-1~bpo70+1
- jessie 8.9.2~rc1-2+deb8u1
- jessie-backports 8.9.5-1~bpo8+1
- testing 8.9.10-2
- unstable 8.9.10-2
DRBDSETUP(8) | System Administration | DRBDSETUP(8) |
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]
[-t { disk_timeout}]
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] [-g { congestion_policy}] [-f {val}]
[-h {val}]
drbdsetup
{ device} syncer [-a {dev_minor}] [-r {rate}]
[-e { extents}] [-v {verify-hash-alg}]
[-c {cpu-mask}] [-C { csums-hash-alg}] [-R]
[-p {plan_time}] [-s {fill_target}]
[-d {delay_target}] [-m { max_rate}]
[-n {ond-policy}]
drbdsetup
{ device} disconnect
drbdsetup
{ device} detach [-f]
drbdsetup
{ device} down
drbdsetup
{ device} primary [-f] [-o]
drbdsetup
{ device} secondary
drbdsetup
{ device} verify [-s {start-position}]
[-S {stop-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-deviceIn 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 sizeYou 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 mark the disk as inconsistent, 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
-b, --use-bmbv
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.
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. Option 4 (disable everything, use "none")
is dangerous on most IO stacks, may result in write-reordering, and if
so, can theoretically be the reason for data corruption, or disturb the DRBD
protocol, causing spurious disconnect/reconnect cycles. Do not
useno-disk-drain.
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
-m, --no-md-flushes
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. Note: Since Linux-2.6.36
(or RHEL's 2.6.32) this method is disabled.
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.
none
The fourth method is to not express
write-after-write dependencies to the backing store at all, by also specifying
--no-disk-drain. This is dangerous on most IO stacks, may result
in write-reordering, and if so, can theoretically be the reason for data
corruption, or disturb the DRBD protocol, causing spurious
disconnect/reconnect cycles. Do not use--no-disk-drain.
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.
-t, --disk-timeout disk_timeout
If the driver of the lower_device does
not finish an IO request within disk_timeout, DRBD considers the disk
as failed. If DRBD is connected to a remote host, it will reissue local
pending IO requests to the peer, and ship all new IO requests to the peer
only. The disk state advances to diskless, as soon as the backing block device
has finished all IO requests.
The default value of is 0, which means that no timeout is enforced. The default
unit is 100ms. This option is available since 8.3.12.
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 timeIn 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. Typically set to the same as
--max-buffers, or the allowed maximum. 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. Typically set to the
same as --max-epoch-size. Small values could lead to degraded
performance. The default value is 2048, the minimum 32. Increase this if you
cannot saturate the IO backend of the receiving side during linear write or
during resync while otherwise idle.
See also drbd.conf(5)
-u, --unplug-watermark val
This setting has no effect with recent kernels
that use explicit on-stack plugging (upstream Linux kernel 2.6.39,
distributions may have backported).
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, yet others don't feel much effect at all. 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
-B, --after-sb-1pri asb-1p-policy
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.
possible policies are:
disconnect
-C, --after-sb-2pri asb-2p-policy
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.
possible policies are:
disconnect
-P, --always-asbp
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.
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.
-g, --on-congestion congestion_policy, -f,
--congestion-fill fill_threshold, -h,
--congestion-extents active_extents_threshold
By default DRBD blocks when the available TCP
send queue becomes full. That means it will slow down the application that
generates the write requests that cause DRBD to send more data down that TCP
connection.
When DRBD is deployed with DRBD-proxy it might be more desirable that DRBD goes
into AHEAD/BEHIND mode shortly before the send queue becomes full. In
AHEAD/BEHIND mode DRBD does no longer replicate data, but still keeps the
connection open.
The advantage of the AHEAD/BEHIND mode is that the application is not slowed
down, even if DRBD-proxy's buffer is not sufficient to buffer all write
requests. The downside is that the peer node falls behind, and that a resync
will be necessary to bring it back into sync. During that resync the peer node
will have an inconsistent disk.
Available congestion_policys are block and pull-ahead. The
default is block. Fill_threshold might be in the range of 0 to
10GiBytes. The default is 0 which disables the check.
Active_extents_threshold has the same limits as al-extents.
The AHEAD/BEHIND mode and its settings are available since DRBD 8.3.10.
syncer¶
Changes the synchronization daemon parameters of device at runtime. -r, --rate rateTo 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.
-p, --c-plan-ahead plan_time, -s,
--c-fill-target fill_target, -d,
--c-delay-target delay_target, -M,
--c-max-rate max_rate
The dynamic resync speed controller gets
enabled with setting plan_time to a positive value. It aims to fill the
buffers along the data path with either a constant amount of data
fill_target, or aims to have a constant delay time of
delay_target along the path. The controller has an upper bound of
max_rate.
By plan_time the agility of the controller is configured. Higher values
yield for slower/lower responses of the controller to deviation from the
target value. It should be at least 5 times RTT. For regular data paths a
fill_target in the area of 4k to 100k is appropriate. For a setup that
contains drbd-proxy it is advisable to use delay_target instead. Only
when fill_target is set to 0 the controller will use
delay_target. 5 times RTT is a reasonable starting value.
Max_rate should be set to the bandwidth available between the
DRBD-hosts and the machines hosting DRBD-proxy, or to the available
disk-bandwidth.
The default value of plan_time is 0, the default unit is 0.1 seconds.
Fill_target has 0 and sectors as default unit. Delay_target has
1 (100ms) and 0.1 as default unit. Max_rate has 10240 (100MiB/s) and
KiB/s as default unit.
-m, --c-min-rate min_rate
We track the disk IO rate caused by the
resync, so we can detect non-resync IO on the lower level device. If the lower
level device seems to be busy, and the current resync rate is above
min_rate, we throttle the resync.
The default value of min_rate is 4M, the default unit is k. If you want
to not throttle at all, set it to zero, if you want to throttle always, set it
to one.
-n, --on-no-data-accessible ond-policy
This setting controls what happens to IO
requests on a degraded, disk less node (I.e. no data store is reachable). The
available policies are io-error and suspend-io.
If ond-policy is set to suspend-io you can either resume IO by
attaching/connecting the last lost data storage, or by the drbdadm
resume-io res command. The latter will result in IO errors
of course.
The default is io-error. This setting is available since DRBD
8.3.9.
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-peerAlias 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 (and this node is "VerifyS"), this command silently "succeeds". In this case, any start-sector (see below) will be ignored, and any stop-sector (see below) will be honored. This can be used to stop a running verify, or to update/shorten/extend the coverage of the currently running verify. 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-sectorSince 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. If you had reached
some stop-sector before, and you do not specify an explicit start-sector,
verify should resume from the previous stop-sector.
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).
-S, --stop stop-sector
Since version 8.3.14, on-line verification can
be stopped before it reaches end-of-device. This can be
Default unit is sectors. You may also specify a unit explicitly. The
stop-sector may be updated by issuing an additional drbdsetup verify
command on the same node while the verify is running.
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 either part of a connected device pair, or disconnected Secondary.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. On a disconnected Primary device, this will set all bits in the out of sync bitmap. As a side affect this suspends updates to the on disk activity log. Updates to the on disk activity log resume automatically when necessary.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-sbThis 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. -f, --forceA regular detach returns after the disk state
finally reached diskless. As a consequence detaching from a frozen backing
block device never terminates.
On the other hand A forced detach returns immediately. It allows you to detach
DRBD from a frozen backing block device. Please note that the disk will be
marked as failed until all pending IO requests where finished by the backing
block 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-devicesDisplay 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-bitmapClears 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
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
- 2.
- DRBD web site
5 Dec 2008 | DRBD 8.3.2 |