This guide has been released to the DRBD community, and its authors The DRBD User’s Guide v. Pacemaker CRM configuration. This document will cover the basics of setting up a third node on a standard Debian Etch installation. At the end of this tutorial you will have a DRBD device that. There may be multiple resource sections in a single file. For more examples, please have a look at the DRBD User’s Guide.
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The host name of each node determines which parts of the configuration apply uname -n. DRBD detected a split brain situation but remains unresolved.
As a remedy, the writing node occasionally sends peer-ack packets to its peers which tell them which state they are in relative to each other.
The default value is 1; a value of 0 turns off the countdown. Call the “pri-lost” helper program on one of the machines.
If both nodes wrote data, disconnect. Currently, it is 8. Default is 0, which means unlimited. In case rs-discard-granularity is not a multiplier of the discard granularity of the backing block device DRBD rounds it up.
Section handlers Parameters after-resync-target cmd Called on a resync target when a node state changes from Inconsistent to Consistent when a resync finishes. By default, rdbd mechanism is turned off.
Dangerous, do not use. Node identifiers can only be reasssigned in a cluster when the cluster is down. Auto sync from the node that was primary before the split-brain situation happened. In case it cannot reach the peer, it should stonith the peer. IO is resumed as soon as the situation is resolved. Instead of two host parameters the connection may contain multiple path sections.
This feature is only available to subscribers. The available policies are io-error and suspend-io. It allows you to detach DRBD from a frozen backing block device.
(5) — drbd-utils — Debian unstable — Debian Manpages
This option can be used to form a chain or tree of dependencies among devices. 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.
No personal information is collected. Never access such a device while DRBD is running on top of it. Defines all nodes of a mesh.
Drbd-documentation – Free Software Directory
In case it decides the current secondary has the right data, call the pri-lost-after-sb on the current primary. Depending on the configuration of the lower-level devices, and the available network and disk bandwidth, this can slow down the overall resync process. drhd
By using this option incorrectly, you run dbrd risk of causing unexpected split brain. Peer nodes need to wait until they receive an peer-ack for releasing a lock on an AL-extent. Dangerous, do not use.
Then you might see “bio would need to, but cannot, be split: If the peer does not reply within ping-timeoutDRBD will close usee try to reestablish the connection. The downside is that the peer node falls behind, and that a resync will be necessary to bring it back into sync. Edit the haresources file, the IP created here will be the IP that our third node refers to. Drdb means delayed successful completion, especially for READ requests, is a reason to panic.
For backward compatibilty reasons, and because on fast links this possibly does not improve transfer time but consumes cpu cycles, this defaults to off. If a node becomes a disconnected primary, it freezes all its IO operations and calls its fence-peer handler. In case it cannot reach the peer it should stonith the peer.
DRBD consists of low-level user-space components which interact with the kernel and perform basic operations drbdsetupdrbdmetaa high-level user-space component which understands and processes the DRBD configuration and translates it into basic operations of the low-level components drbdadmand a kernel component.
This can be useful in combination with a cluster manager which cannot manage DRBD resources: