TOPIC:

For years I've used hyper-v to host and replicate my HO based web site. I just converted to xenserver and to gain some measure of HA I installed HA-Lizard on three servers in a pool. The servers are just old PCs (Q6600, 4GB memory, 1 NIC, 1TB disk, etc.) that otherwise work adequately to host a simple web site.

With hyper-v I could replicate my website VM and if the primary host failed I could just start up the replicated VM on the replication host.

With HA-Lizard (not SCSI) I hoped for something similar. While the docs repeatedly say "HA" I couldn't determine what that meant outside of just auto restarting a VM. So I pulled the plug on a pool server running a test website vm and waited to see what happened. The log reported that the vdi (vm disk) was not available, which would be true, but nothing was started on another pool server (error starting VM).

Does the basic HA-Lizard do anything other than auto-start VMs? Am I missing a setting to get the ha-lizard-enabled VMs to replicate to the others servers and so can start if the primary fails?

I've read through Version 2.1.3 pdf multiple times and Googled extensively, but I just can't figure out what HA-Lizard is suppose to do (HA wise) when a server fails.

HA-lizard is similar to xenserver's HA It will protect you from host failures and start any affected VMs on a surviving host. In both cases ( HA-lizard and Xenserver's own HA feature) your pool is required to have some form of shared storage so that all hosts in your pool have access to the same disk images. This is generally the case with HA on most hypervisors.

Where HA-lizard differs is that there is a second package you can install alongside HA-lizard, iscsi-ha, which can be used to convert your local storage into a form of redundant shared storage. Also, HA-lizard is the only HA option available that supports pools with 2 hosts. In this case you would get the results you are expecting but the pool would be limited to 2 hosts. There is a reference design guide on the website that documents all of the steps for buiding a 2 host hyperconverged cluster. There is also a script available that automates all of the steps for you. A YouTube video describes the procedure for running the automated installer.

You also have another HA option which would be to use the third host as an iSCSI San or nfs server. In this case, your current installation of just the HA-lizard package would give you the results you are looking for.