User id's with values greater than 65536 ( or is it 65535? )
don't work. For instance, I can create a user with uid
100,000. That user can't log in. Watching syslog during
the login shows a session open for the user, then
immediately close. 'su' spits at the username with a
invalid arguement error and refuses to set the userid to
This has become an issue at NCSU where the eos/unity system
now has ~70,000 users.
The kernel's UID type is only 16 bits. Sorry. When this
is fixed in the kernel, it will work elsewhere.
You might try experimental 32-bit uid support, available at: