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  • 1.  MS Cluster on 2 ESXi hosts

    Posted Aug 30, 2018 08:20 AM

    HI Guys , My client is asking if we can have a MS cluster across two ESXi hosts with physical RDMs. I have implemented this on many other sites , the catch being this one only has two ESXi hosts .

    Considering its cluster across box , with a KB driven compulsory DR ANTI rule required , would it be possible to ever patch ESXi ? Would it be "supported/possible" to disable the DRS anti rule , power down one of the MS cluster VMS , and vmotion it to the ESXi host carrying VM 2 ? Pretty sure this requires 3 ESXi hosts to safely implement , but none of the KBs officially state that as a requirement .

    So ESX1 running MSCLUSTERVM1

    ESX2 Running MSCLUSTERVM2

    Would we fail MS cluster over to MSCLUSTERVM2 , and Shut down MSCLUSTERVM1 .

    Move MSCLUSTERVM1  to ESX2 and Patch and reboot ESX1

    It does not sound like a good plan , but will it work / supported ?



  • 2.  RE: MS Cluster on 2 ESXi hosts

    Posted Aug 30, 2018 11:02 AM

    It is okay but, only during the upgrade duration and hope nothing happens to ESXi-2 in the meantime. Also, there is no need to move VM-1 to ESXi-2. It can stay on ESXi-1 in powered off state. In that case, you don't have to disable the anti-affinity rule.

    Please consider marking this answer as "correct" or "helpful" if you think your questions have been answered.

    Cheers,

    Supreet



  • 3.  RE: MS Cluster on 2 ESXi hosts
    Best Answer

    Posted Aug 30, 2018 12:53 PM

    HI , SK , thanks for the input , I was specifically concerned about when i need to do maintenance / patch one of the ESXi hosts.

    I have gone and tested this on another client , and it does NOT allow you to move VM1 to the same ESX2 where VM2 runs , even if VM1 is powered down . ( DR ANTI disabled )

    This client will just have to buy one more ESXi host to make this a sustainable solution .

    Error while trying to cold vmotion to the ESXi2



  • 4.  RE: MS Cluster on 2 ESXi hosts

    Posted Aug 30, 2018 02:31 PM

    You don't have to move the VM to another host in the first place. In case you want to do maintenance on ESXi-1, VM-1 can stay on ESXi-1 in powered off state. Similarly, VM-2 can stay powered off on ESXi-2 during the maintenance. You do not have to do anything apart from powering off the VMs. Needless to say, more the no. of hosts higher are the availability options :smileyhappy:

    Cheers,

    Supreet



  • 5.  RE: MS Cluster on 2 ESXi hosts

    Posted Aug 31, 2018 05:54 AM

    Ok , but to for example Patch ESX1 , i need to enter Maintenance mode .

    I cannot do that while powered down VM1 on it .



  • 6.  RE: MS Cluster on 2 ESXi hosts

    Posted Aug 31, 2018 09:24 AM

    You can. While entering the maintenance mode, do not select the option 'Move powered off VMs'.

    Cheers,

    Supreet