The only difference, etcher checks that the write was correct, this is nearly always redundent
(and does make it less likely that you will make a.... of=wrong.... mistake,, be careful, use lsblk)
About a year ago,, cd to wherever you want the backup to be, maybe a usb stick?
dd if=/dev/emmc bs=1M |gzip > emmc.backup (replace /dev/emmc with correct mmcblkX, maybe bs=4M might be a little smaller)
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Do not do this from a booted system, you want /dev, /proc, /run to be empty,,,, ie from a SD or usb boot
(and does make it less likely that you will make a.... of=wrong.... mistake,, be careful, use lsblk)
About a year ago,, cd to wherever you want the backup to be, maybe a usb stick?
dd if=/dev/emmc bs=1M |gzip > emmc.backup (replace /dev/emmc with correct mmcblkX, maybe bs=4M might be a little smaller)
-----
Do not do this from a booted system, you want /dev, /proc, /run to be empty,,,, ie from a SD or usb boot