Can I Update a Live USB?

I made a persistent Live USB with the usb-creator, and I was wondering if I can just update as one normally would, or if there are special procedures I need to take.

Solution 1:

If your live usb was created with persistence then it can be updated. However, to fit an entire Linux distribution into a small space it has been compressed & made read only via the squashfs method. So when it updates it recreates the updated parts of the file system outside of the squashfs, taking up a much larger space.

My live Kubuntu 16.04 had 500 MB of updates which finished using 4 GB of space - which fills up a normal casper-rw file. I had made a 8 GB casper-rw partition, hence I still had space.

I suggest you stick to security updates only.

When I made my usb I created 4 partitions: for the main file system, casper-rw for persistence, home-rw for my stuff, and a ntfs partion for sharing files. If the live iso images are updated, then the usb can be updated by copying the new iso files into the old usb. I'm also thinking about unsqashing the file system, updating it in virtualbox and resquashing it.

Solution 2:

Startup Disk Creator now produces an ISO9660 partition that is read only.

There is no "persistence" option. Since there is no casper-rw persistence file, there is no place for updates to be stored.

If you want an updateable/upgradeable Bootable USB, do a Full install as you would to internal drive. (Best to unplug internal drives first).

Solution 3:

There are no special procedures. But your setting would not be saved if you have not made a persistent Live USB. You can read more about it on Ubuntu Wiki.

Solution 4:

None of the existing ISO9660-based live operating systems provide a kernel update feature: the kernel and the initrd are the only components that a live operating system cannot update, because they lay outside of the data persistence partition (if any) and the system partition is, as said, ISO9660-formatted.

After some years of asking me why, I found the liveng whitepaper on Read the Docs.

The full aim of the liveng project is to give the Community a set of best practices in order to turn a common Debian Linux live into a live(ng) operating system which features:

native encrypted persistence;
kernel update (on a live ISO 9660 filesystem!);
UEFI, with UEFI Secure Boot compatibility, with a real efi partition.