Ha with 2 Nodes/iSCSI
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Hi folks,
Ive currently got one Server running XCP-ng in my Lab, im wondering if its possible to have a 2 node Ha setup? have a Master and second as a backup server not just for maintenance but if one server goes offline? my VMs are running over iSCSI with a 4G LAGG via two Switches for redundancy. Could this work?
Cheers.
Jack.
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It's possible but not recommended (two nodes means split brain can occur).
Do you really need HA?
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@olivierlambert Hi, thanks for your reply. I want something for a backup incase the server goes offline. But I suppose a offline backup machine could work?
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HA and backup are 2 completely different things.
Backup is the possibility to get data from the past, even if you lose all your hosts.
HA is made to keep your VMs running (or reboot them on another host) if one host is dead.HA won't protect your data, just the availability of your services installed in your VMs.
In reality, not a lot of people need HA for their VM. But everyone need backup.
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@olivierlambert Hi sorry I meant a backup machine incase the main server goes offline. I am hosting mail servers and Web servers also CCTV VMs and I need something that will keep them running incase the main server goes offline.
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HA is a beast you need to use carefully. For something like you said, it would be better that if once every 5 year you got a host down, you boot the VM on the other manually.
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@olivierlambert OK I get what you mean now. Cheers
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You are welcome
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@olivierlambert Hey i have another question, If i run the VM on the second Server does it matter if the RAM is the same althought CPUs are the same? Make and Model of the RAM or can that cause a problem? Another question if i have Host 2 online and i run different VMs on each of the host meaning Mail and Web Server on one host and Cloud Storage Server on the other using the same iSCSI storage can this be done by adding a second host to XO? or could it be possible to combine both servers into 1 for more Memory?
Cheers.
Jack.
