SureBackup question: More RAM in one Host for labs?

[cstemaly]

I have 5 ESXi 5.0 U2 hosts, and have gotten SureBackup running (great product btw). I keep about 25% of the RAM free on each of my hosts for HA purposes (each has 64GB), but some of the on-demand labs I would like to roll out, even adjusting the RAM of each VM in the SureBackup lab config, put me a bit over. Certainly, I can migrate some servers over to other hosts, but I was wondering if a better solution might be to add more RAM to the server used by my virtual lab.

I have read that you should keep your RAM amounts consistent between all of your hosts for HA math purposes, but if I'm just going to add, say, 64GB to one host for SureBackup Lab purposes, then I should be fine, right?

[foggy]

This is more vSphere configuration-related question - you will be definitely fine in terms of SureBackup.

I may be wrong, but as far as I understand, the recommendation to have all hosts balanced in terms of memory comes from the fact that cluster resource utilization will not be optimal otherwise (you will have "unused" memory on the largest host as it will be taken out of the equation during HA slot calculations). In your case, this memory will not be unused as it will be used for SureBackup.

[cstemaly]

Thanks Foggy, that confirms how I suspected this to work.

[dellock6]

Just to clarify, even if it's not Veeam related.
Slot calculations kick in only if HA cluster is configured with the policy "number of hosts the cluster can tolerate to loose". If you use for example cpu and ram percentage you do not suffer from slot reservations, anche it becomes easier to have unbalanced nodes inside the same cluster. By the way, nowadays percentage reservation is the suggested way of configure a cluster.

Luca.