For such cases, make sure you activate the "hybrid" USE flag and take care of the necessary changes, explained below.
If you try to (even involuntarily) disturb the server's rotation, you may be added to a temporary ban list.
Copy to all the questions about VIRTIO in the following kernel compile section (but be sure to read the prompts before pressing enter). Once you have returned to the shell, do: argument here means that the compile will run concurrently with 2 jobs.
Change this to the number of your machine's cores plus one to best shorten the compile time.
After you have started the compile, grab a cup of coffee and relax!
Write the partition table and quit after you have made the right alternations. A little hint here: as rsync is costly, many servers don't allow too many frequent syncs.