TS-4720 eMMC Backup/restore

Click to download the latest 4GB SD card image.

WARNING:

Make sure the SD and eMMC filesystems are mounted read only while writing any images. If dd is used to read or write a disk while a filesystem on it is mounted read/write this can result in a corrupt image.

First boot to the initramfs. These steps should not be run from the full Debian environment, so to get back to the initramfs, first run:

tshwctl --removejp 1 && reboot

Once you are in the initramfs, mount a network share or usb drive containing the emmc image.

Write an Image to eMMC

# Check /mnt/root.  If it shows a file "root.version", you can proceed.
# If it shows nothing, you need to wait for the Debian filesystem
ls /mnt/root/


# Plug in a thumbdrive formatted with ext2/3/4 or fat32/ntfs
mkdir /mnt/usbdev
mount -o ro /dev/sda1 /mnt/usbdev
umount -l /mnt/root/

# Tell sdctl to pause so we don't kill it during a burst
killall -USR1 sdctl
# Allow time for any buffered writes to finish
sleep 5 
killall sdctl

# The dblstor-disable command only tells the card to
# ignore any doublestore metadata on the eMMC during
# this write.  It does not prevent reading/writing doublestore
# formatted media.
# This command can be expected to take about 10 minutes
sdctl --lun 1 -z 65536 --dblstor-disable -i /mnt/usbdev/emmc-image.dd
reboot

These steps can write the eMMC image to use a single-card #Doublestore, or you can write the SD Image] to not use doublestore.

Save an image from eMMC

# Plug in a thumbdrive formatted with ext2/3/4 or fat32
mkdir /mnt/usbdev
mount /dev/sda1 /mnt/usbdev
umount -l /mnt/root/

# Tell sdctl to pause so we don't kill it during a burst
killall -USR1 sdctl
# Allow time for any buffered writes to finish
sleep 5 
killall sdctl

sdctl --lun 1 -z 65536 --dblstor-disable --nbdserver lun1:disc
nbd-client 127.0.0.1 7500 /dev/nbd1
dd if=/dev/nbd1 bs=4M of=/mnt/usbdev/emmc-image.dd
umount /mnt/usbdev
sync