Issues when upgrading with HA enabled

  • Admin

    @txsastre yes, Citrix officially recommend to disable HA before upgrading. And always starting with the master.

  • XCP-ng Team

    I added a warning in the RC post.

  • @olivierlambert
    The reason to use HA kinda is useless if I have to disable it everytime I'm doing something 🙂 In my way on thinking: I should enter maintenance mode, so the host moves all running VMs over to the host2. And then upgrade it, move everything to node1 and repeat. At least there is not downtime. If I need to disable it...unless I move everything and then disable HA on master, reboot and upgrade it. And then re-enable HA again. But then I would like to move the master role back to host1 (1st master). I couldnt find a way to transfer the master role. Is it possible, if yes, where can I find it?

    @txsastre I didnt upgrade the master when going from 7.4 to 7.5-rc1. That's why I lost connection (stuck in reboot state). I shutdown every VM and upgrade the slave too. Then reboot both hosts and now 7.5-rc1 is working.

    EDIT: Btw this time I was talking about updating through CLI, locally on the hosts with "yum update".

  • Admin

    Hmmm. Correction: it's not "everytime I'm doing something", it's "when I'm upgrading between XCP-ng versions", which isn't an operation you'll do everyday. This is a Citrix recommendation, not our own, I suppose they got enough experience to know that their own HA is doing crazy stuff when you upgrade your pool.

    Disabling HA is straightforward, and just time to reboot your pool master (first).

  • @olivierlambert

    Hmm I've a feeling there is misunderstanding here 😄 Disabling HA doesnt effect the VMs running on the slave at all? And then when I've rebooted the master and enable HA again on the "slave (old master) I can transfer the VMS over back to it and then repeat the steps for all hosts? If thats the case then its ok 😃 It's just that I understood it as, if I disable the HA I can't get the connections back between the hosts without have to shut everything down and upgrade all hosts and then start everything up again.

    EDIT: "Disabling HA is straightforward, and just time to reboot your pool master (first)." - Yes I have learned my lesson the first time 🙂
    If I just wanna upgrade files with "yum update" -command through the CLI I dont need to disable it everytime?
    Is there a way to manually move the "master role"?

  • Admin

    Disabling HA won't do anything. Just migrate your VMs from the master (to any slave host), reboot it. That's pretty much it. Do the same for all your hosts (migrating VMs, rebooting, re-migrate VMs on it).

    When it's done, just re-enable HA.

  • Admin

    Don't mix things. yum update can be used to upgrade (from 7.4 to 7.5) but most of the time it's use to do simple updates (some doesn't require even to reboot the host).

    HA won't interfere until you decide to reboot a host.

  • @olivierlambert
    I was answering txsastre in the same post thus the misunderstanding I think. 🙂 And when I was going to disable HA on my host I got a message that indicated that it would break everything.
    But the way you describe it, it sounds ok. So basically, everytime one need to upgrade something, major/minor thats the way to do it, regardless if reboot is necessary or not?

  • Admin

    If you don't need to reboot, don't touch HA 🙂 HA is tricky when it comes to have hosts to reboot. I would avoid it in general BTW… more dangerous than helping in most of the cases.

  • @olivierlambert
    Okej, its that part that's tricky 😃 Yea maybe so, but it's cool. And makes the uptime better even if it's just a lab. I've been using vmware for a while at my last work. But the licensing is not nice for a homelab. So this is my first time with xcp-ng (xenserver). I'll try updating tomorrow. Thanks.

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