-Is there a difference in performance between these two kernels?

-Is it recommended to switch to Latest 2.6 Paravirt?

-Is the switch painless?

I'm currently running Ubuntu 8.04 and I plan on updating to 10.04 when it's released.

No.


For Ubuntus starting with 9.10, mandatory. They have a new udev which will not work with 2.6.18 kernels; when you upgrade, be sure to set it to Paravirt or your system will refuse to boot.


The paravirtualized clock is detached from the host by default, so you'll want to install ntpd to keep it accurate. That's it, to my knowledge. If you're using custom kernel modules (you probably aren't), they'll have to be recompiled.

Give it a whirl today before you upgrade -- I run all of mine on paravirt with no issues.

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Disclaimer: I am no longer employed by Linode; opinions are my own alone.

I've been running on paravirt for many months now with no issues. I do it mostly because I otherwise have a stock Debian stable install, and with pv I can use the distro kernel that everything else expects.