Sysadmin/Migrate virtual machine: Difference between revisions

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   # virsh vol-create-as boot new.img 1G --format raw
   # virsh vol-upload --pool boot new.img existing.img
+=== Copying LVM volumes across machines ===
+Create the new volume, format and mount it:
+ # virsh vol-create-as nvme-pool new-root 20G
+ # mkfs.ext4 -L new-root -O mmp,flex_bg,extent,uninit_bg,sparse_super /dev/nvme-pool/new-root
+ # tune2fs -c -1 -i 0 /dev/nvme-pool/new-root
+ # mkdir /new-root
+ # mount /dev/nvme-pool/new-root /new-root
+Copy the contents of the remote filesystem (this can be done while the VM is online, but you might want to shutdown any running database to get a consistent snapshot):
+ # rsync -PHAXphax lightwave:/ /new-root/
+Don't forget to unmount your new filesystem!
+ # umount /new-root
+ # rmdir /new-root
+=== Importing a VM from existing disk files ===
+ # virt-install -v --accelerate --nographics --vcpus 2 --ram 1024 --os-type linux --os-variant=ubuntu20.04 --network bridge:br0 --disk vol=boot/NEWVM-boot.img,bus=virtio --disk vol=nvme-pool/NEWVM-root,bus=virtio --name NEWVM --import
+The new VM will boot and probably fail to mount the root because the UUID changed.
+You can fix this by dropping into grub the usual way:
+* virsh start --console NEWVM
+* press ESC before the kernel starts
+* press e to edit a menu entry
+* modify the kernel command line (for example, root=/dev/vdb)
+* hit ctrl-x to boot
+After booting, remember to update your grub.cfg and test it:
+ # update-grub
+ # reboot
 === How to migrate a file-based guest to LVM (online method) ===
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-=== Alternative to convert file based VM to block based LVM (Assumes server is treehouse) ===
+=== Alternative to convert file based VM to block based LVM ===
 Stop the VM