Arch Linux

gipeltruth

Member

Registered: 2019-09-29

Posts: 6

Read-only root partition causes authentication failure

When I put the ro option on my root partition in /etc/fstab, I get the authentication failure error next time I try to login.

I've see that other people have this problem as well.

How do I make my root partition read only on startup while still being able to log in?

It would also be helpful if anyone knows why this happens, and if there are specific directories that must be writable on boot or something.

Zod

Member

From: Hoosiertucky

Registered: 2019-03-10

Posts: 636

Re: Read-only root partition causes authentication failure

The Internet...read it.

https://events.static.linuxfound.org/si … e-2016.pdf

gipeltruth

Member

Registered: 2019-09-29

Posts: 6

Re: Read-only root partition causes authentication failure

Solved it by mounting /var as tmpfs.

So I guess systemd-logind needs files in /var to be writable at boot.
Don't know which files though.
If I did, then I could mount just those as tmpfs and not the entire /var directory.

loqs

Member

Registered: 2014-03-06

Posts: 19,089

Re: Read-only root partition causes authentication failure

You could use audit to monitor /var.
Edit:
At a guess you could try changing the account entry for pam_tally2.so in /etc/pam.d/system-login to

account    required   pam_tally2.so        onerr=succeed

Last edited by loqs (2020-01-28 19:34:18)