I use ubuntu server 10.04 on a fairly good machine, with 2.40 dual-core processor and 2GB RAM.
My users login with ssh or samba. I have setup LDAP with PAM to sync user accounts between unix and samba. When I allowed about 90 users to login over ssh at once the server refused login for many users. I am using dropbear as ssh server. Even samba logins failed for many users. I need to allow at least 100 users to login at once. Is there anyway to do this?
I think what you're looking for is in the man sshd_config, the MaxSessions and MaxStartups fields
http://www.manpagez.com/man/5/sshd_config/