Mar 17 2012

CMAN & Two-Nodes cluster: prevent rgmanager “Quorum Dissolved”.

Ordinarily, the loss of quorum after one out of two nodes fails will prevent the remaining node from continuing (if both nodes have one vote.)

Special configuration options can be set to allow the one remaining node to continue operating if the other fails.
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Mar 13 2012

LVM on top of DRBD “Failure: (104) Can not open backing device”.

Using Proxmox VE, in 2 members cluster configuration with LVM on top of DRBD, makes possible to have FileSystem Data Redundancy and support OnLine VMs Migration between Host Controllers.

DRBD refers to block devices designed as a building block to form high availability (HA) clusters.
This is done by mirroring a whole block device via an assigned network. DRBD can be understood as “Network-Based RAID1”.
For detailed information please visit Linbit.

After rebooting a controller it is possible to see that DRBD is not properly working and the rebooted node is indicating: “Failure: (104) Can not open backing device.” and DRBD’s DS is “Diskless”.
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