I do have locally this file onto my BTRFS fs: $ ls -l *minimal* -rw-r--r-- 1 qemu qemu 221249536 Mar 24 17:15 install-amd64-minimal-20150319.iso lrwxrwxrwx 1 tfoerste tfoerste 34 Apr 25 21:08 minimal.iso -> install-amd64-minimal-20150319.iso My host file system is a 240 GB SSD: # fdisk -l Disk /dev/sda: 223.6 GiB, 240057409536 bytes, 468862128 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 57608924-3129-49BA-8255-3EDD4D4973B9 Device Start End Sectors Size Type /dev/sda1 2048 6143 4096 2M BIOS boot /dev/sda2 6144 33560575 33554432 16G Linux swap /dev/sda3 33560576 468862094 435301519 207.6G Linux filesystem When I boot the minimal ISO using the grub2 entry : menuentry "Gentoo Minimal" { set isofile='/home/tfoerste/Downloads/minimal.iso' loopback loop $isofile set root=(loop) linux /isolinux/gentoo root=/dev/ram0 init=/linuxrc looptype=squashfs loop=/image.squashfs cdroot isoboot=$isofile vga=791 dokeymap initrd /isolinux/gentoo.igz } then /dev/sda3 is auto-mounted onot /mnt/iso - as seen in the dmesg, but that dir doesn't exist - see attached screen shot. (FWIW same for the live-DVD livedvd-amd64-multilib-20140826.iso)
Looks like initrd has mounted HDD partition which contains .iso to /mnt/iso, but then it does pivot_root and this result in losing access to that partition after LiveCD boot: mount says "already mounted", losetup says it's mounted to /mnt/iso, but /mnt/iso doesn't exists after pivot_root. Tested on admincd-amd64-20150924.iso. I think possible solution may be to mount --bind /mnt/iso to /newroot/mnt/iso before pivot_root.
