Preparing to unpack .../iucode-tool_1.5.1-1_amd64.deb ...
Unpacking iucode-tool (1.5.1-1) ...
Selecting previously unselected package intel-microcode.
Preparing to unpack .../intel-microcode_3.20151106.1_amd64.deb ...
Unpacking intel-microcode (3.20151106.1) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up initramfs-tools (0.122ubuntu8) ...
update-initramfs: deferring update (trigger activated)
cp: cannot create regular file '/cdrom/casper/initrd.gz.new': No such file or directory
dpkg: error processing package initramfs-tools (--configure):
 subprocess installed post-installation script returned error exit status 1