Hi, I've committed today a driver for the Xen paravirtualized disk interface also known as Blkfront. Despite being pretty stable for me so far, it's not enabled by default at the moment. Therefore I'm looking for additional tests on different Xen versions and EC2 instances to ensure robustness and performance of the software.
To enable the driver, uncomment the xbf line in the kernel config file (/sys/arch/amd64/conf/GENERIC) and re-configure and re-build the kernel. The system will automatically switch all available wd* disks to sd* but, unless you have opted out of using disklabel UIDs in the /etc/fstab, there's no configuration tweaking required. Please report successes and failures. In case of a reproducible issue, please enable the XEN_DEBUG define in /sys/dev/pv/xenvar.h, rebuild you kernel and send me relevant lines from the log (copied from the console or /var/log/messages). Cheers, Mike