/usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?).
run-parts: /etc/kernel/postrm.d/zz-update-grub exited with return code 1
Failed to process /etc/kernel/postrm.d at /var/lib/dpkg/info/linux-image-3.8.0-34-generic.postrm line 328.
dpkg: error processing linux-image-3.8.0-34-generic (--remove):
subprocess installed post-removal script returned error exit status 1
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)
You might not be able to upgrade the kernel on your VPS. Contact your VPS provider and get them to upgrade the kernel for you.