DRBD ( Distributed Replicating Block device ) is a Linux block device that is designed to mirror a whole block device over a network link. Today the team developing DRBD released version 8.0
Among many bug fixes and improvements in the new version we find support for primary/primary ( two way synchronization ) for distributed file systems such as OCFS2 and GFS, optional peer authentication with a shared secret and improved tunable after-split-brain recovery strategies.
Here is the original announce:
We have something to celebrate here...
DRBD - 8.0.0
This is the official entry to the changelog:
* No effecitve changes to rc2.
But I want to remind you about the changes relative to the 0.7
release of DRBD:
* Removed support for Linux-2.4.x
* Cleanup of the wire protocol.
* Added optional peer authentication with a shared secret.
* Consolidated state changes into a central function.
* Improved, tunable after-split-brain recovery strategies.
* Always verify all IDs used in the protocol that are used as pointers.
* Introduced the "outdate" disk state, and commands for managing it.
* Introduced the "drbdmeta" command, and require the user to create
* Support for primary/primary (for OCFS2, GFS...)
* Replaced the sync-groups with the sync-after mechanism.
* The "common" section in the configuration file.
* Replaced the generation counters (GCs) with data-generation-UUIDs
* Improved performance by using Linux-2.6's BIOs with up to 32k per
IO request. Before we transferred only up to 4k per IO request.
* A Warning if the disk sizes are more than 10% different.
* A connection teardown packet to differentiate between a crash
of the peer and a peer that is shut down gracefully.
* External imposable SyncPause states, to serialize DRBD's resynchronisation
with the resynchronisation of backing storage's RAID configurations.
* Backing storage can be hot added to disk less nodes.
* Prepared for advanced integration to Heartbeat-2.0
* Changed internal APIs so that missed writes of the meta-data super
block are reported as they happen.
* The http://usage.drbd.org sub project.
* Rewrote the scanner/parser of drbd.conf. 10 times smaller/faster and
easier to maintain.
* Asynchronous meta-data IO [ Code drop from the DRBD+ branch ]
To have our release policy more transparent in the future:
Bugfix releases will increase the 3rd number, e.g. 8.0.1, 8.0.2 etc...
Releases that introduce small new features will increase the second
number, resetting the third number: 8.1.0 etc...
In the next weeks we will try to update the http://www.drbd.org
with a bit of new content.
Oh, yes, and then we will prepare it for inclusion into
Linus' mainline Linux.