Active/ Active HA Cluster on Centos 8

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btb
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Active/ Active HA Cluster on Centos 8

Post by btb » 2020/09/25 05:26:13

I am setting up two node HA Cluster on Centos 8 and all the documents that I am referring are Active/ passive HA. I procured the servers to share both nodes and one of the node cannot accomodate all CPU/ Memory requirements of the virtual machines. I have two servers and one iscsi based storage.

Can you point me where I can get any reference for Active/Active HA cluster configuration so that VMs work on both nodes and can migrate VMs without any downtime?

Thanks in advance for your time and help.
btb.

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TrevorH
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Re: Active/ Active HA Cluster on Centos 8

Post by TrevorH » 2020/09/25 16:15:54

If one of your servers cannot handle the load of all the work then you do not have an HA cluster because as soon as one machine goes, the workload will all failover to the other one which will promptly crash due to lack of resources...

But aside from that, a cluster running VMs is not restricted to running them all on one node. You can tell it to run them in a balanced way. But you'd have to give a lot more detail about how you set it up, what resources you have, where the VM storage resides etc.
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btb
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Re: Active/ Active HA Cluster on Centos 8

Post by btb » 2020/09/27 17:46:35

Dear TrevorH,

thanks for the asnwer.

Yes, I know and my system cannot fully recover if one of the node fails but at least I can start very critical VMs from the working node.

The problem I have with Active/ Passive configuration is that only one of the node (unstandby node) can see the mapped iscsi storage. I can not run VMs on both nodes simultaneously and migrate VMs across the the nodes.

btb
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Joined: 2020/09/25 05:20:44

Re: Active/ Active HA Cluster on Centos 8

Post by btb » 2020/09/27 17:51:18

I have a two node cluster and HP MSA iscsi based storage. The nodes have very limited storage space but faire CPU and memory but the MSA storage has 4TB space. I have planned to put all the VMs on the storage and tried to run on both nodes. In case of node failurity, critical nodes will continue to run from the working nodes.

btb
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Joined: 2020/09/25 05:20:44

Re: Active/ Active HA Cluster on Centos 8

Post by btb » 2020/10/06 19:39:08

Hello again,

I came across Ovirt to run VMs on both nodes and maintain a little bit of HA. Kindly advise if you have come across with Ovirt. Currently, my both nodes are running Centos 8.

thanks

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