Comment 6 for bug 704022

Whether using the pv devices or the emulated ones should hardy make a difference with respect of the timeouts and data loss which is reported here. It has a performance benefit for the communication between the instance and the Xen host, though. And we are about to release kernel updates to have the required drivers built-in and not as modules (like they are now). But those are currently in testing (for 11.04 and 11.10).

For the timeouts, I wonder whether that could be an effect of storage on ec2 usually being network attached, together with a high(er) general utilization. Actually moving from emulated to pv devices could make that even worse. Surely there also is a chance that the pv driver handles such delays/contention better than the emulated device driver.

But it should be possible to switch to the pv drivers even with the current images. Just add the pci-platform, xen-netfront and xen-blkfront drivers into /etc/initramfs-tools/modules, then run update-initramfs -u and make sure that the root device in /boot/grub/grub.cfg and /etc/fstab is using uuid or labels (because on reboot with pv drivers enabled device names will switch from hd to xvd for the block devices).