How to disable password expiry without chage? I have an ubuntu linux image, which I use for my single board computer. When I write it the media (it's an sdcard), then boot and log in, it asks me to change the password. Since I can mount and modify the sdcard content with another computer before actually performing the boot, I'd like to disable the password expiry. I know that on a _running_ system I can use `chage`, but in this case, the target system is on the card. Is it possible to do it?

From `man chage`:

>
> -R, --root CHROOT_DIR
> Apply changes in the CHROOT_DIR directory and use the configuration
> files from the CHROOT_DIR directory.
>

So just `chroot` to the mount point of your sdcard.

Editing `shadow` to delete the expiry times bypasses the normal mechanisms. It could in principle fail if `shadow` is backed by a database, your `login` reads credential from NIS, and other similar situations, but you probably don't have any of these oddball situations on a sdcard. So editing `shadow` should work too.