How do you create a new vm from an imported disk

pnunn

Hi Guys,

I'm trying to migrate my lab setup from kvm to xcp-ng.

I am trying to migrate my first test machine and have hit a bit of a road block.

I have converted and imported the old disk (qcow2 image to vhd conversion and import) and can see the disk in the sr OK.

What I can't figure out is how to create a new vm based on this disk.

I have seen some things suggesting that its the template type which dictates whether I can attach an existing disk, but so far I haven't managed to find one that lets me. So far, I only seem to be able to create a new disk and use that.

Is this possible? If so how is it done?

Ta.
P.

Danp

I would do it like this --

Create the VM using the desired template
Delete the "default" disk from the VM
Attach the imported disk

olivierlambert

I would do the same: create a VM without disk with the closest template possible (eg Ubuntu for an Ubuntu imported VM), don't boot it. Then, attach an existing disk, and boot it

pnunn

Close... but it can't find a boot disk by the looks of things.

I'll have to play further.

P.

olivierlambert

What do you mean? Can you be more explicit?

pnunn

The VM tries to boot to the newly added .vhd disk, but is unable to find anything to boot from.

P.

olivierlambert

Try to boot with a live CD (eg Ubuntu) and access the disk content from there. Maybe you need to chroot and reinstall grub, and reload initrd if Xen drivers aren't there.

pnunn

I found the instructions here https://github.com/xcp-ng/xcp/wiki/Migrating-from-other-hypervisors and it talks about using dracut on the vm before the export, do you think this is worth a try?

olivierlambert

That might do the trick, yes Worth trying!

pnunn

Groan... maybe testing with a machine what actually boots in kvm to start with would be a good idea... trust me to pick a broken machine to test with... now.. lets try that again shall we? Sorry for wasting your time all... will report back how I go with a working machine.

P.

olivierlambert

hahaha no worries, it happens

pnunn

So very very close.

I have migrated a ubuntu 19.04 machine from KVM to my lab, and managed to get it to boot, until!! I tried to attach the guest-tools cd to install them.

I got an error that said the cd is not fully installed, restart the vm.

I tried that, and now the machine refuses to boot at all with the old "unknown error".

vm.start
{
  "id": "3ffe9f7e-cf37-3003-348f-766c7059ff49"
}
{
  "code": "VDI_MISSING",
  "params": [
    "OpaqueRef:a70e1e33-4a17-4d6b-961f-6e4044aed54d",
    "OpaqueRef:0aa6eb4a-1c93-4227-952c-ec47fb3b29fe"
  ],
  "call": {
    "method": "VM.start",
    "params": [
      "OpaqueRef:72c1f833-98d9-41b8-80b4-f531cdd77861",
      false,
      false
    ]
  },
  "message": "VDI_MISSING(OpaqueRef:a70e1e33-4a17-4d6b-961f-6e4044aed54d, OpaqueRef:0aa6eb4a-1c93-4227-952c-ec47fb3b29fe)",
  "name": "XapiError",
  "stack": "XapiError: VDI_MISSING(OpaqueRef:a70e1e33-4a17-4d6b-961f-6e4044aed54d, OpaqueRef:0aa6eb4a-1c93-4227-952c-ec47fb3b29fe)
    at Function.wrap (/home/pnunn/xen-orchestra/packages/xen-api/src/_XapiError.js:16:12)
    at _httpRequestPlus.default.post.readAll.then.text (/home/pnunn/xen-orchestra/packages/xen-api/src/transports/json-rpc.js:35:27)
    at tryCatcher (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/util.js:16:23)
    at Promise._settlePromiseFromHandler (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/promise.js:547:31)
    at Promise._settlePromise (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/promise.js:604:18)
    at Promise._settlePromise0 (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/promise.js:649:10)
    at Promise._settlePromises (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/promise.js:729:18)
    at _drainQueueStep (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/async.js:93:12)
    at _drainQueue (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/async.js:86:9)
    at Async._drainQueues (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/async.js:102:5)
    at Immediate.Async.drainQueues [as _onImmediate] (/home/pnunn/xen-orchestra/node_modules/bluebird/js/release/async.js:15:14)
    at runCallback (timers.js:705:18)
    at tryOnImmediate (timers.js:676:5)
    at processImmediate (timers.js:658:5)"
}

olivierlambert

Eject the CD and try to boot.

pnunn

Ughh. thought I tried that. Just did it with the machine off and its now booting again, thank you, however, that doesn't get the tools installed.

After some mucking around, it seems I can mount pretty much any other .iso from the iso store but note the guest-tools.iso for some reason. It just does nothing now (as in, the pulldown list is just showing "select disk(s)".

pnunn

OK, seems I wasn't trying hard enough.

I was trying to mount the tools under the iso list, but when I look further down the list to xc-ng Tools it turns out I can mount the tools from there as long as I do it manually (mount /dev/sr0 /media/blahblah).

Installed now, all good.