linux

OK, this is driving me crazy.  ISPConfig is a great piece of software.  It can manage your web sites, and related services (such as DNS, FTP, mail, etc.) well, and it handles the config files with pretty good care, and it rarely breaks.  But, the installation experience is so twisted that I can't bear.  And if I would only have to tolerate this at fresh installs, then I'd just try to live with it, but facing the same old problems once more each time I try to update the installation is way beyond acceptable.

Today I had this problem where Fail2ban was keeping on blacklisting an IP address, even though it was in the ignoreip list in /etc/fail2ban/jail.conf.  After double-checking everything on the server, and googling desperately, I found out that up to version 0.8.2, Fail2ban had a bug which caused only the first IP in the ignoreip list to take effect.  And guess what?  Ubuntu versions before gutsy have older versions of Fail2ban.  After a bit of digging, I found out the patch which had

If you happen to run Ubuntu Server (at least, up to version 7.04) and use the Courier POP3 or IMAP server, and you're watching your log files closely, you've seen error messages such as the below one in /var/log/syslog:

May 21 01:14:10 server4 authdaemond: PAM [dlerror: /lib/security/pam_foreground.so: undefined symbol: pam_set_data]

Server monitoring is something server admins put off until, well, it's too late.  Server admins have all experienced clients calling in to let them know that a service on their server is not working.  This can be unfortunate and embarrassing at the very least.  I thought I'd document a number of utilities I use to monitor Linux servers.