DRBD

Distributed Replicated Block Device

Links

• Homepage
• Building a redundant pair of Linux storage servers using DRBD and Heartbeat
• [https://serverstack.wordpress.com/2017/05/31/install-and-configure-drbd-cluster-on-rhel7-centos7/
• http://www.asplund.nu/xencluster/page2.html
• http://www.linux-ha.org/wiki/Main_Page
• DRBD 8.3 Third Node Replication (stacked)
• Configure sync rate
• https://serverfault.com/questions/740311/drbd-terrible-sync-performance-on-10gige

See also: http://www.gluster.org/ and http://ceph.com/

• Xen and DRBD

Support

• Linbit
• Hastexo

Tools

• LCMC, a GUI for managing LVM, DRBD in pacemaker environment]

Docs

• Resizing drbd xen lvm (dont worry about the meta-data if that's not internal) (bug it seems wrong, using phy: instead of drbd: )
• http://www.asplund.nu/xencluster/page2.html

Recovery

• Recovering from a DRBD split-brain scenario in heartbeat
• [1]
• [http://www.drbd.org/users-guide/s-split-brain-notification-and-recovery.html Split brain notification and automatic recovery

GFS on DRBD

• http://sourceware.org/cluster/wiki/DRBD_Cookbook
• http://www.piemontewireless.net/Storage_on_Cluster_DRBD_and_GFS2

Cheatsheet

Make device primary

drbdadm primary yourdeviceID

or

drbdsetup /dev/drbdX primary -o

FAQ

show configuration

drbdsetup show

update network settings

drbdsetup net-options 10.0.0.1 10.0.0.2  --sndbuf-size=2M

mount: unknown filesystem type 'drbd'

Usually means your node is not primary. If you're sure you know what you're doing you can use

mount -t ext4 /dev/drbd1 /drbdmount

reload configuration

drbdadm adjust all

show configuration of resource

drbdsetup /dev/drbd0 show