Highly Available iSCSI ALUA (Asymetric Logical Unit Access) Storage with Pacemaker and DRBD in Dual-Primary mode – Part1
I already wrote a post on this topic so this is kind of extension or variation of the setup described here Highly Available iSCSI Storage with SCST, Pacemaker, DRBD and OCFS2. The main and most important difference is that thanks…
Highly Available iSCSI Storage with SCST, Pacemaker, DRBD and OCFS2 – Part2
This is continuation of the Highly Available iSCSI Storage with SCST, Pacemaker, DRBD and OCFS2 series. We have setup the HA backing iSCSI storage and now we are going to setup a HA shared storage on the client side. iSCSI…
Highly Available iSCSI Storage with SCST, Pacemaker, DRBD and OCFS2 – Part1
SCST the generic SCSI target subsystem for Linux, allows creation of sophisticated storage devices from any Linux box. Those devices can provide advanced functionality, like replication, thin provisioning, deduplication, high availability, automatic backup, etc. SCST devices can use any link…
GlusterFS metadata split brain recovery
While investigating an error related to failed documents I came across following error in the GlusterFS healing daemon log file: [2015-11-08 23:22:38.700539] E [afr-self-heal-common.c:197:afr_sh_print_split_brain_log] 0-gfs-volume-vol1-replicate-0: Unable to self-heal contents of ” (possible split-brain). Please delete the file from all but…
GlusterFS internals
GlusterFS stores metadata info in extended attributes which is supported and enabled by default in the XFS file system we use for the bricks. This is different approach then some other distributed storage cluster systems like Ceph for example that…
MySQL High Availability and Load Balancing with Keepalived
What we want to achieve here is have a MySQL HA two nodes cluster in Master-Master mode and load balance the instances using as less hardware as possible. The role of the LB will be given to Keepalived that will…
VIP(EIP) fail over with Keepalived in Amazon VPC across availability zones
This example covers VIP failover in AWS VPC across AZ’s with Keepalived. The main problem in AWS is that this provider is blocking the multicast traffic in the VPC’s. To circumvent this we need to switch to unicast for the…