I have a couple of Raspberry Pis running at different sites. I can access all of them over SSH and all of them are running read only file system.

I need to fully replace the software on some of this and I would like to do this over SSH. I know it is a bit dangerous but it will save me some time and if it fails I can always go there and replace the SD card by hand.

So I figure what I should do is:
1. Create a RAM disk
2. Copy commands to RAM disk: dd, reboot
3. From my remote computer issue something like:
dd if=software.img bs=1m | ssh root@raspberrypi /mnt/ram/dd of=/dev/mmcblk0 bs=1m

I have two questions. Would this work if we hav