WHM

Fixing Common Perl Issues – cPanel

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Sometimes you’ll notice that a certain function of cPanel or WHM was working fine, now all of a sudden you’re getting results that you’ve never seen before. Believe it or not, many problems with cPanel functionality related to processes running off of scripts is because of a perl corruption. To resolve this, usually the first step you should take is running a cPanel update, as this will correct most issues. If the problem persists, you may need to recompile perl from it’s core.

Before we start, here are a few of the most common indicators that there is a perl issue on your server:

  • Accounts are not created properly, like missing files
  • Frontpage extensions refuse to be installed
  • Stats won’t run, result in cryptic perl errors
  • Error messages that look like this:
(internal death) Sat Jun 3 21:01:55 2006 [32719] error: List::Util object version 1.14 does not match
 bootstrap parameter 1.18 at /usr/lib/perl5/5.8.7/i686-linux/XSLoader.pm line 92.
==> Starting cpbandwd (bandwidth monitoring for IMAP/POP)
Can't locate Class/Std.pm in @INC (@INC contains: /usr/local/cpanel /usr/lib/perl5/5.8.7/i686-linux
/usr/lib/perl5/5.8.7
BEGIN failed--compilation aborted at /usr/lib/perl5/site_perl/5.8.7/Unix/PID.pm line 8.
Compilation failed in require at /usr/local/cpanel/bin/cpbandwd line 15.
BEGIN failed--compilation aborted at /usr/local/cpanel/bin/cpbandwd line 15.

In some cases, the error is specific about a perl module missing. If this is the case, look for the perlmod format in the error message. In the above example you can see ‘List::Util’ being referenced, so you can try to reinstall that either manually or from WHM:

/scripts/perlinstaller –force List::Util

If reinstalling the perl module itself does not solve the problem, you can recompile perl. First, do a perl -v from command line to see what version you are running. Then follow these steps:

wget http://layer1.cpanel.net/perl587installer.tar.gz
tar xvzf perl587installer.tar.gz
cd perl587installer
./install

/usr/local/cpanel/bin/checkperlmodules

If you are running 5.8.8, use the installer from:

http://layer1.cpanel.net/perl588installer.tar.gz

The recompile may take as long as 20 minutes to complete.

Downgrading MySQL to 4.x – cPanel

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If you’ve upgraded MySQL via WebHost manager, the downgrade process is slightly more complex than the upgrade. This tutorial mainly covers a downgrade from 4.1 to 4.0, but also applies to downgrading from 5.x to 4.x.

*Back up all databases before proceeding, as all existing databases will be deleted!

1. Uninstall existing MySQL packages:

rpm -qa | grep -i mysql-

This should return a list of several rpm’s installed. You will need to remove them all with the rpm -e command .

2. Delete the active MySQL directory:

rm -Rfv /var/lib/mysql

3. Get cPanel Ready

Edit /var/cpanel/cpanel.config and change the version to the one that you are downgrading to (4.0, 4.1, etc)

mysql-version=4.0

Make sure that MySQL updates aren’t being skipped:

rm /etc/mysqldisable
rm /etc/mysqlupdisable

4. Install MySQL:

/scripts/mysqlup –force

5. Update the perl module:

/scripts/perlinstaller –force Bundle::DBD::mysql

Finally, recompile Apache and PHP via Web Host Manager.