Bug#540000: live-initramfs: can not mount /dev/loop0 (/live/image/live/filesystem.squashfs) on //filesystem.squashfs
Someone's gotten their knickers in a twist it seems.
Anyways, I just ran into this myself, so I'll take a shot at providing some useful information.
For starters, I'm hitting this bug when using the Xen LiveCD scripts, 0.8.2 from here:
My setup is somewhat peculiar, and I thought it might be Xen's scripts at fault until Google showed this this gem of a bug. Cause is unknown, and I've not had to report a Debian bug before, so hopefully the below information is relevant.
Release: Stable (Lenny)
Error from /live.log is:
Begin: Running /scripts/live-premount ... done.
Begin: Running /scripts/live-realpremount ... done.
Begin: Mounting "/live/image/live/filesystem.squashfs" on "/filesystem.squashfs" via "/dev/loop0" ... mount: mounting /dev/loop0 on //filesystem.squashfs failed: No such device
Checcking into /dev, all eight loopback devices appear to be present, their major is 7, and minor is 0 through 7, and all are of type block (b). Running "file" on the filesystem.squashfs in binary/live reports it as "Squashfs filesystem, little endian, version 3.1", so I suspect the usual issue of the squashfs revision not matching the kernel can be ruled out.
I am testing this on a Xen-enabled system, and using Xen's step-by-step scripts in their amd64/subdirectory to build things, then once I have a sample ISO file built, I'm booting that under Xen to see the results. It's possible that booting an amd64 VM under an amd64 Hypervisor could contribute, but I want to eliminate the fault being in the live-helper/live-initramfs scripts first, since several Google pointers are coming back to this bug.
My setup is made further peculiar, as I've had to mirror the entire Debian apt repository, as my build system is not connected (and cannot be connected) to the Internet. I'm using dhttpd and apt-proxy to serve out the entire lenny/squeeze/sid packages + security updates from this morning. Only testing the Xen scripts on building a Lenny-based image, as Xen under Squeeze/Sid appears to have changed drastically. I doubt this contributes to the cause of the bug, but worth mentioning just in case.
I've also tried downgrading the debootstrap, live-helper, and live-initramfs packages to their Lenny versions (I was previously using the Sid version), and that hasn't affected the outcome at all. Booting the image on an actual DVD yields the same results as in the VM, so I suspect something is not 100% kosher with the way the SquashFS filesystem is being built.
I'll post a similar report to the Xen-Users list just incase this might be a bug with their scripts, but as far as I can tell, their scripts are just basic wrappers around the Debian tools.