We've set up a Red Hat Enterprise Linux 5 server and can log into it remotely just fine (with root and other users), but if I try to log in locally with a keyboard and monitor connected to the machine, I keep being returned to the login prompt. If a login is incorrect, I get an error message, but if it is correct then the screen just blanks and shows the login prompt again.
While booting the only error message that comes up has to do with SNMPD, so I don't think it's related.

I read this post on the forum which seemed like a similar problem but it didn't help (I wasn't getting the "Module is unknown" message he was). I also read another post somewhere that said he was having the problem because the server was trying to use AD to authenticate, but I checked that and it's not the case with our server.

From what I'm told (I didn't set up the server myself) it used to work fine, but then "something" happened one day that made it do this.

Any help would be appreciated. Thanks.

Try booting in single user mode and take a look at /var/log/messages and /var/log/secure for a start

1 members found this post helpful.

Thanks kbp.
So it looks like I actually was getting getting the "module is unknown" error, I just wasn't getting it on the screen. I had already checked /var/log/messages before posting and there was nothing that seemed interesting there, but I didn't know about /var/log/secure. I looked at that, and here is what's written to it when I try logging in locally.

The machine/OS is x86_64, so if it's trying to use ELFCLASS32 I can see why it's giving that error. Any idea on how I can fix it?

Ah, got it!

Edited /etc/pam.d/login and changed

to

and it worked. Thanks for your help.

Glad you're up and running, pam references usually say '/lib/security/$ISA/<module>' which will avoid architecture issues

cheers