Hi,
 
I followed the instructions on: http://wiki.grml.org/doku.php?id=persistency
 
Some data:
 
blkid:
/dev/sr0: UUID="2014-11-14-14-44-49-00" LABEL="grml64-full 2014.11" TYPE="iso9660" PTUUID="30667644" PTTYPE="dos"
/dev/sda1: LABEL="persistence" UUID="6eb587f3-5f92-4be4-812b-7575f2738145" TYPE="ext2" PARTUUID="dff7adbd-01"
/dev/loop0: TYPE="squashfs"
 
persistence.conf:
/ union
 
grep persistence /var/log/live/boot.log:
+ LIVE_BOOT_CMDLINE=BOOT_IMAGE=/boot/grml64full/vmlinuz initrd=/boot/grml64full/initrd.img boot=live live-media-path=/live/grml64-full/ bootid=grml64full201411 apm=power-off vga=791 nomce persistence debug=1
+ overlays=live-rw home-rw persistence custom-ov
+ find_persistence_media live-rw home-rw persistence custom-ov
+ overlays=live-rw home-rw persistence custom-ov
+ probe_for_gpt_name live-rw home-rw persistence custom-ov /dev/sda1
+ overlays=live-rw home-rw persistence custom-ov
+ probe_for_fs_label live-rw home-rw persistence custom-ov /dev/sda1
+ overlays=live-rw home-rw persistence custom-ov
+ [ persistence = live-rw ]
+ [ persistence = home-rw ]
+ [ persistence = persistence ]
+ echo persistence=/dev/sda1
+ [ persistence = custom-ov ]
+ result=persistence=/dev/sda1
+ [ -n persistence=/dev/sda1 ]
+ ret= persistence=/dev/sda1
+ probe_for_gpt_name live-rw home-rw persistence custom-ov /dev/sda
+ overlays=live-rw home-rw persistence custom-ov
+ probe_for_fs_label live-rw home-rw persistence custom-ov /dev/sda
+ overlays=live-rw home-rw persistence custom-ov
+ [  = persistence ]
+ probe_for_file_name live-rw home-rw persistence custom-ov /dev/sda
+ overlays=live-rw home-rw persistence custom-ov
+ mount_persistence_media /dev/sda probe
+ backing=/live/persistence/sda
+ mkdir -p /live/persistence/sda
+ mount -t unknown -o rw,noatime /dev/sda /live/persistence/sda
mount: mounting /dev/sda on /live/persistence/sda failed: No such device
+ rmdir /live/persistence/sda
+ probe_for_gpt_name live-rw home-rw persistence custom-ov /dev/sr0
+ overlays=live-rw home-rw persistence custom-ov
+ probe_for_fs_label live-rw home-rw persistence custom-ov /dev/sr0
+ overlays=live-rw home-rw persistence custom-ov
+ [ grml64-full 2014.11 = persistence ]
+ probe_for_file_name live-rw home-rw persistence custom-ov /dev/sr0
+ overlays=live-rw home-rw persistence custom-ov
+ mount_persistence_media /dev/sr0 probe
+ backing=/live/persistence/sr0
+ mkdir -p /live/persistence/sr0
+ [ /live/persistence/sr0 != /live/medium ]
+ mount --move /live/medium /live/persistence/sr0
+ mount -o remount,rw,noatime /live/persistence/sr0
+ echo /live/persistence/sr0
+ backing=/live/persistence/sr0
+ [ -z /live/persistence/sr0 ]
+ path=/live/persistence/sr0//live-rw
+ [ -f /live/persistence/sr0//live-rw ]
+ path=/live/persistence/sr0//home-rw
+ [ -f /live/persistence/sr0//home-rw ]
+ path=/live/persistence/sr0//persistence
+ [ -f /live/persistence/sr0//persistence ]
+ path=/live/persistence/sr0//custom-ov
+ [ -f /live/persistence/sr0//custom-ov ]
+ umount /live/persistence/sr0
+ rmdir /live/persistence/sr0
+ [ -n  persistence=/dev/sda1 ]
+ echo persistence=/dev/sda1
+ echo persistence=/dev/sda1
+ media=persistence=/dev/sda1
+ mount_persistence_media /dev/sda1
+ backing=/live/persistence/sda1
+ mkdir -p /live/persistence/sda1
+ mount -t ext2 -o rw,noatime /dev/sda1 /live/persistence/sda1
+ echo /live/persistence/sda1
+ backing=/live/persistence/sda1
+ [ -z /live/persistence/sda1 ]
+ [ -r /live/persistence/sda1/persistence.conf ]
+ include_list=/live/persistence/sda1/persistence.conf
+ close_persistence_media /dev/sda1
+ backing=/live/persistence/sda1
+ [ -d /live/persistence/sda1 ]
+ umount /live/persistence/sda1
+ rmdir /live/persistence/sda1
+ newmount=/root/lib/live/mount/persistence/sr0
+ mkdir -p /root/lib/live/mount/persistence/sr0
+ mount -o move /live/persistence/sr0 /root/lib/live/mount/persistence/sr0
 
 
Any hints?
 
Thanks,
   Michael