/dev/sdb2 is the partition device file. /mnt is where the partition is mounted. So you want to write the output file to the mountpoint.so I pulled up a tutorial (actually google AI explained it pretty well) on how to do this but apparently I am doing something it doesn't care for because I keep getting the error. with another quick google I find something telling me I need the destination disk mounted (yes my source disk was unmounted before I attempted this) and how do do so by using this command:dd: failed to open `/dev/sdb2/backup.img` : Not a directoryand that seemed to work as it should without any errors. I again tried the DD commandCode:
sudo mount /dev/sdb2 /mntand received the same error.Code:
sudo dd if=/dev/sda of=/dev/sdb2/retropie-bk-up.img bs=4M status=progress
I'm not exactly sure what I'm not doing correctly and any further googeling doesn't seem to give me many more options.
i know that if is input file/source (all of sda) and of is output file (sdb2 which is a single partition) and that's about all I'm understanding in this process.
Code:
sudo dd if=/dev/sda of=/mnt/retropie-bk-up.img bs=4M status=progressStatistics: Posted by rpdom — Fri Aug 15, 2025 9:46 pm