Linux Tips, Tricks, Tutorials & Fixes

Issue: Sometimes you get frequent emails from your VPS server regarding nameservers fail : nameserver failed @ Sat May 24 01:34:46 2011. A restart was attempted automagically. Service Check Method: [check command] Cmd Service Check Raw Output: Fixed ownership on /etc/named.conf Fixed ownership on /etc/rndc.key Fixed ownership on /etc/rndc.conf named is not running If you start named service, it still show the same message Fix: Recent versions of Bind distributed by RedHat and CentOS enable strict zone checking at startup time. This setting can potentially cause problems for Bind service, I have fixed this by adding in /usr/lib64 >> the following symlinks : ln -s libisc.so libisc.so.11 ln -s libdns.so libdns.so.22 On the previous version of Bind, these little mistakes in the zone files were ignored, latest version - not so much. Zone files updated/fixed and everything works fine.

ERROR: Connection dropped by imap-server It's an issue with extremely large attachments in the mail spool. I think, the issue is the following: with large mail spools or with large attachments within the mailspools, imapd requires a lot more time to parse through the spool. SquirrelMail times out while waiting for imapd to respond. (the default time-out in SquirrelMail 1.x is 15 seconds). Fix:  1. Remove large attachments from the mail spool. 2. Convert the mail spool to a binary format such as mbx that can be parsed and handled more quickly than a straight text file. Use a larger timeout while waiting for the IMAP read request to complete. Thick clients such as Outlook have a configurable timeout from 1 minute to 10 minutes... I believe SquirrelMail 2.x has better support for a longer timeout. If you want to increase the timeout in SquirrelMail 1.x go to line 444 of functions/imap_general.php and change the last parameter of the fsockopen() call from 15 [seconds] to so...

Issue: Sometimes when you connect MySQL through Jailshell to setup email piping, you get the following error in mail header: Error: Could not connect to the database Fix: There may be more than one reason to occur this issue. You need to check following things to troubleshoot: 1. From the email header we can see the error "Could not connect to the database" and you need to check if "/var/tmp/mysql.sock" symlink is missing in the server. # ll /var/tmp/mysql.sock lrwxrwxrwx 1 mysql mysql 25 Apr 29 20:30 /var/tmp/mysql.sock -> /var/lib/mysql/mysql.sock= The above result is showing that symlink is present. If not, create one using the following command: # ln -s  /var/tmp/mysql.sock /var/lib/mysql/mysql.sock= 2. Cpanel jailshell access to mysql requires the use of "127.0.0.1" specifically instead of "localhost", and since the WHMCS autoresponder pipe script access mysql, the configuration.php file needed to be updated to change ...