Replicating to same pool storage
We're planning this for tomorrow so any last minute thoughts will greatly be appreciated.
We have a NAS we want to share between hosts. There are 3 hosts in total. 2 of these are our "primary" hosts, each has 2 SR's.
We want to setup a CR backup to replicate Server 1 SR 1 to Server 2 SR2 and Server2 SR1 to Server 1 SR2 as part of a availability job. I have opened a support ticket and Yannick recommends we keep the 2 hypervisors in their own pools, however, he says it is indeed possible for us to create a replication job the way we envision below. The problem is just that we're going into production with this so curious if there are others doing something similar and if there is a chance we may run into unknown issues down the line? As I now know one cannot simply remove a host from a pool without destroying all vm's on the local SR, I am worried that we go ahead with this and we end up with a case where the CR does not work as planned and at that time have to figure out a way to reset and do over.
So, in a nutshell, is there a chance we may run into issues down the line? Should we rather keep the servers in seperate pools and only have 1 of the 2 hypervisors have access to the NAS and if the hypervisor goes down we can then figure out how to move it to the other hosts?
@mauzilla I personally think having the CR job operate between 2 different pools is a better idea.
I am curious though, are these servers located in the same physical location? If so why not try going with high availability instead of a CR job? https://xen-orchestra.com/blog/xenserver-and-vm-high-availability/
I haven't really done HA setups with XCP-ng before, so can't really speak to how good it is. But IMO CR and other backup jobs like that are more meant for geo replication and stuff like that (i.e. a disaster recovery scenario with some offsite XCP-ng host). Which is why I'm asking about location, personally don't see the benefit to CR if in the same physical location, I'd be more interested in HA at that point.
This is just my two cents though.