Using grml64small and following http://wiki.grml.org/doku.php?id=persistency from step by step I get the following error in the boot.log
Begin: Copying live media to ram ... Begin: mount -t tmpfs -o size=241260k /dev/shm /live/medium_swap ... done. Begin: Running /scripts/live-realpremount ... done. Begin: Mounting "/live/medium/grml64-small.squashfs" on "//grml64-small.squashfs" via "/dev/loop0" ... done. mount: mounting /dev/sda1 on /live/persistence/sda1 failed: No such device mount: mounting /dev/sda3 on /live/persistence/sda3 failed: No such device mount: mounting /dev/sda on /live/persistence/sda failed: No such device mount: mounting /dev/sdb on /live/persistence/sdb failed: No such device /init: line 230: can't open /tmp/custom_mounts.list: no such file done. Begin: Configuring fstab ... done. Begin: Preconfiguring networking ... done.
Help please