I just upgraded from 10.10 to 11.04. During the upgrade process, it said there was a problem setting up initramfs-tools and I needed to do sudo dpkg --configure -a
So once I got 11.04 started for the first time, I did that. This is the output.
Setting up initramfs-tools (0.98.8ubuntu3) ... update-initramfs: deferring update (trigger activated) Processing triggers for initramfs-tools ... update-initramfs: Generating /boot/initrd.img-2.6.38-8-generic gzip: stdout: No space left on device E: mkinitramfs failure cpio 141 gzip 1 update-initramfs: failed for /boot/initrd.img-2.6.38-8-generic dpkg: error processing initramfs-tools (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: initramfs-tools
After searching around, it seemed like this was a problem of insufficient space in my /boot partition. It is only 100 MB and this has never been a problem before, but despite deleting all but the latest kernel I still get the same message.