4700 Backup/Restore SD
If backing up on a separate workstation, keep in mind windows does not have direct block device support needed to write these images. You will also need to determine the SD card device. You can usually find this in the output of 'dmesg' after inserting the SD card and you will typically see something like '/dev/sdb' as the block device and '/dev/sdb1' for the first partition. On some newer kernels you will see '/dev/mmcblk0' as the block device and '/dev/mmcblkop1' for the first partition. For these examples I will use the '/dev/mmcblk0' format.
If you are backing up directly on the board you will likely need to use some kind of offboard storage like a thumbdrive or external hard drive. Make sure you have any nbd devices unmounted before trying to restore new ones.
You can find the latest SD card image here. Make sure you decompress the image first before writing.
Note: | Not all SD cards are created equally, over time they tend to shrink in size due to automatic retiring of bad blocks. All of Technologic System's images are 10% smaller than the target disc size. We STRONGLY recommend following that same practice on any mass-replicated images. |
From Workstation
Backup
Entire SD card
dd if=/dev/mmcblk0 of=/path/to/backup.dd bs=32k
Note: | Not all SD cards are created equally, over time they tend to shrink in size due to automatic retiring of bad blocks. All of Technologic System's images are 10% smaller than the target disc size. We STRONGLY recommend following that same practice on any mass-replicated images. |
Kernel
dd if=/dev/mmcblk0p2 of=/path/to/zImage bs=32k
Initrd
dd if=/dev/mmcblk0p3 of=/path/to/initrd bs=32k
Restore
Entire SD card
dd if=/path/to/backup.dd of=/dev/mmcblk0 bs=32k
Kernel
dd if=/path/to/zImage bs=32k of=/dev/mmcblk0p2
Initrd
dd if=/initrd bs=32k of=/dev/mmcblk0p3
From SBC
Backup
Entire card
dd if=/dev/mmcblk0 of=/path/to/backup.dd
Kernel
dd if=/dev/mmcblk0p2 of=/path/to/backup.dd
Initrd
dd if=/dev/mmcblk0p3 of=/path/to/backup.dd
Restore
The entire card from SBC
dd if=/path/to/2GB-mSD-4700-latest.dd of=/dev/mmcblk0
Kernel
dd if=/mnt/root/zImage of=/dev/mmcblk0p2
Initrd
dd if=/mnt/root/initrd of=/dev/mmcblk0p3