Troubleshooting Your Linux Server

Most of the time, things run just fine with a well configured Linux server. Unlike Microsoft systems, those based on UNIX, such as Linux and FreeBSD, have proven to provide better reliability and longer uptimes. The only arguments on this point come from the Microsoft camp and their special interest buddies in the press.

Yet, when things to wrong, as the result of installing software or performing upgrades, it can sometimes be a challenge to find the answers. Provided on this page is a compilation of some issues experienced by our users and their resolution.

sshd issues

ssh disconnects, GLIBC_PRIVATE not defined

ssh disconnects immediately after successful login with the following error:

relocation error: /lib/libnss_dns.so.2: symbol __res_maybe_init, version GLIBC_PRIVATE 
not defined in file libc.so.6 with link time reference

cause: happened after upgrading to glibc to 2.3.5.

resolution: restart the sshd service, the upgrade also affected apache server and it required restart. further services may be affected.

bash says "I have no name!"

after ssh login the bash shell prompt looks like this:

 I have no name!@bulldog ~#

(bulldog is the actual hostname of the boxen) cause: happened after upgrading to glibc to 2.3.5.

resolution: getpwuid is in pwd.h which is included by shell.c , the function is get_current_user_info () which sets current_user.user_name = _("I have no name!"); if the code entry = getpwuid (current_user.uid); fails to get the user id name.

still seeking a solution...