I know about Clonezilla and copy pasting partitions with gparted, but can I just use dd to copy a partition with batocera to a USB stick and will it then boot from the stick? Do I have to set the boot flag or take any other steps?
Thank you for any tips.
It might work, but probably not without a little tweaking.
A lot of things will reference drive identifiers or drive path to know where to mount them. These things don’t get copied by dd.
huh?
Isn’t it the other way around?
I once cloned an nvme with dd and had to physically remove one of the two, because they had the same id and the bios couldn’t differentiate between them and would randomly boot into either the first or the second one, inconsistently.
And removing either one would boot into an identical system with everything mounted and working. Which caused some confusion until I realized that the id was copied over.
So unless you didn’t use the id in fstab, you should be fine. Sure the device path may differ, but that can happen anyway to usually devices should be referenced by id.
Thanks, so just update the UUID in fstab for the stick? Or is there more?
If you dd your entire laptop drive to the entire flash drive it should be able to boot. It might not work the same with just one partition though. Also, how big is your USB stick!?!?
Lmao they are huge these days! But I’m talking about a 40gb partition, cloning it to a 64gb stick.
You can’t even buy 2gb sticks anymore :/
Small USB flash drives are still available, you just won’t find them in the local stores. There are expensive, industrial grade drives from places like digikey and dirt cheap, no name drives from Chinese sellers where they will print your logo on them for free if you buy a hundred of them.
One partition is not enough. You also need to copy a EFI boot partition and create a correct partition table manually. And note that you cannot get a correct result when partitions you are copying are mounted. You need to boot some live system to do this.
I’ve heard that systemd-boot can do it with just one partition but I don’t know howww also somebody please eli5 BTRFS to me, my brain’s doing the full-sponge thing.
You can just use `# cat /dev/your-disk > /dev/your-stick, no need for a (dd) scalpel there.
If your system uses UUID’s in /etc/fstab, you have to change them to match the current partitions to have it bootable. lsblk -o+UUID is nice for that.
… not if you took a blue pill overdose …
Ok, thanks. That sounds pretty good.
If i want to compress it and save it as a backup can I do
cat /dev/sda3 | gzip -9 > drive.img.gz
?
Yes, but like @kuneho said, since “deleted” stuff only is marked as deleted (not wiped), there’s always a bunch of random on the “empty” space part of a disk, which compresses badly.
Do cat /dev/zero > /path/to/mounted/partition/zeroes and delete it after cat errored out because no space, to fill the “empty” space with zeroes.
That worked really well! I got a 50gb partition with about 30gb free space into a 10gb zipped image. Is there any way to show progress during the operation like with dd’s status=progress?
#Big tip: use chatGPT to help you with commands.
You can say something like “I want to backup my entire file system using [this program]. I want to create a tar file, and then copy that to an external drive. I want the program to display progress while it’s copying, then verify the files have been copied correctly once it has finished. I am using [whatever distro]. Please give me the commands I need to achieve this.”
Then it will spit out the commands you need to input with the correct syntax.
The best part is that you can then ask it to clarify any parts of its answer so you can learn how it all works and make sure the commands are doing what you asked. And if your computer spits out an error, just paste that back into chatgpt and it will help you resolve it.
Seriously, chatgpt is like a 24 hour on call Linux guru friend. It’s saved me so much time and effort over the last few months doing things like this.
Swear to God. I hope someone develops something so I can just say what I want to do in the terminal and an AI will create the command then prompt “run this command? Y/N/E” E to explain it
What usually specified in fstab and other configs are FS UUIDs, not partition UUIDs. They are kept when cloning with dd.
