Topics created by McHenry

@McHenry Look at this post: VM limits - CPU Limits

@Andrew

Got it. So the DR host may have fewer resources than the production host, which would work for a failure of one or two VMs but not for a total failure of the production host whereby all VMs need to run on the DR host.

Is it only RAM that is a consideration between hosts? Meaning if my production host has 16 vCPUs and my DR host only has 8 vCPUs can I still set the VM to use 16 vCPUs and it will work on both hosts?

@McHenry Yes, XCP sees and uses all threads (8 core + SMT x2 threads = 16 logical cores). So you can assign all of them to a VM as long as the VM can use them.

XO shows 16 "cores" (total threads) and 1 socket. It also shows hyperthreading is enabled. XCP/XO does not differentiate between cores, threads, E-Cores or P-Cores.....a thread is an assignable core resource.

You can assign 16 logical vCPU that includes real cores and SMT threads.

Some programs do not work well with hyperthreading in a VM environment. So you may wish to disable SMT depending on the workload.

Is it PV, HVM or a PVHVM VM?
Health Check can't work on HVM because there are no tools.

@McHenry @nick-lloyd With todays release of Xen Orchestra (XOA) version 5.100 there's now support for custom ACLs based around tags. These will prove really useful when your setting up the XOA with its ACL for your clients to access self service, while ensuring that they can't access the other's pools and VMs etc.

@McHenry Base copies are not copy per say but a base of a VDI chain.

XO coalesce

Here you can see that A and B are base copies for the snapshots C and E while D is the active VDI.
You can find more info on this page: https://docs.xcp-ng.org/storage/#-coalesce

That's why warm is magical: it's a lot less risky while providing a reasonable availability 🙂

@McHenry +1. Never found how to do it....

Just going to XO / Home / Pools / pool-1 and pressing "Add hosts" button, selecting host-2 worked OK this time. So no detaching host from a pool and attaching to new pool ... just a button 🙂

@BenjiReis

Got it, thank you.

@McHenry Check the contents of the VM's blocked-operations parameter. This is from one of my VMs --

# xe vm-param-get param-name=blocked-operations uuid=e764e6fb-5e18-35dd-cfb6-ddf83d32e1fd start_on: Start operation for this vm is blocked, clone it if you want to use it.; start: Start operation for this vm is blocked, clone it if you want to use it.

Both the start and start_on operations should be blocked on CR created replicas.

@stephane-m-dev
In the schedule You can select force full backup

@Andrew

Got it. As we only have a single production server there is no shared storage so I guess the idea of a pool is mute.

So the tools are visible but XO can't find them. Thanks for the feedback, we'll dig.

@ph7

I am using an Incremental Replication backup (aka Continuous Replication) and I understand this is the same as Delta however Delta uses remotes whereas I.R. uses host storage.

That's indeed a solution. We could also maybe "revert" the condition for people with like 500 VMs to healthcheck except one.

@olivierlambert

Thanks Oliver, lots to learn.

p.s. Congrats on the 8.3 launch.

@McHenry

Hey

Whatever happened to this? Have you solved it?

After looking at your comment I found this https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/manage/manage-hyper-v-integration-services which explains how to disable those. I haven't done this before.

@McHenry

https://xcp-ng.org/docs/api.html

Restarting the API
Sometimes, you might want to restart the toolstack (API and storage stack). You can do it with the following command from the host console (or directly with Xen Orchestra):

xe-toolstack-restart

TIP
Restarting XAPI won't affect any running VMs. However, all backup/export tasks will be removed.