Author Archives: pingd

CRON ERROR: failed to open PAM security session: Protocol not supported

Got an interesting report of an error on one of our servers. I was told crons for a user account on our server weren’t running. I tailed the cron log (/var/log/cron) and came to find these errors:

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ZFS on Linux RC10 released!

The ZFS on linux team has released a new version of SPL and ZFS with multiple benefits to users. The new version is 0.6.0-rc10 and our guide found here is being updated now: Installing ZFS RAID-Z on CentOS 6.2 with … Continue reading

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Pick random line from text file with bash and shuf.

So lets say you have a text file called list.txt with entries like: What if you wanted to pick a random entry? The easiest solution is to use the ‘shuf’ tool, which is standard on CentOS as part of coreutils. … Continue reading

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New ZFS on Linux release (RC9).

We have one of the most comprehensive guides on the internet for ZFS. Please check the updated guide for assistance with installing ZFS on Linux, specifically CentOS 6.2 here: Installing ZFS RAID-Z on CentOS 6.2 with SSD Caching

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No module named cElementTree yum update error

Found yum broken on a legacy CentOS 5.x server while installing updates. The error was: root # yum update There was a problem importing one of the Python modules required to run yum. The error leading to this problem was: … Continue reading

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Installing ZFS RAID-Z on CentOS 6.2 with SSD caching.

Updated August 16th, 2012 I recently had a project that required data storage with deduplication, data integrity assurance, and hardware fault tolerance. Instead of going with a traditional hardware RAID solution I opted to test out ZFS. My configuration utilized … Continue reading

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KVM Hardware Virtualization on CentOS 6.2 Dedicated Servers

I wrote this guide to show you how to do a proper KVM setup on your CentOS dedicated server. We will be using VNC and connecting to the dedicated server remotely from your workstation. I realize there are a lot … Continue reading

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List all installed Perl modules on server.

Sometimes you may need to figure out which Perl modules you have installed on your server. This can be very useful when cloning a server for a development project. The easiest way to see every installed module and the module’s … Continue reading

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Can’t remove or re-add a cPanel addon or parked domain?

Sometimes you may find that a domain just won’t go away from cPanel. You may be trying to simply remove an addon domain or a parked domain, or you may be trying to re-add a domain that was at some … Continue reading

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Download a backup over 2GB through cPanel instead of Apache.

Apache/FTP in some configurations can’t serve files that are over 2GB. This has been largely corrected on most HEL/CentOS cPanel servers, but there are legacy exceptions. There is a way to get such a large file via a cPanel function. … Continue reading

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