Red Hat Enterprise Linux 6: Why to Upgrade - Why to Hold Off

We lease all of our hardware, which poses some interesting problems in itself, but also gave us a three or four year cycle for upgrading the operating system and software stack. In the past few years, we have transitioned to virtual machines, and gained a bit of hardware independence. Now the hardware can come and go, and we can run the same operating system image without the need, or opportunity, to upgrade the operating system.

Coupling this hardware independence with Red Hat’s long four-phase lifecycle, we can, theoretically, go for ten years without upgrading the operating system in the virtual machines, and still receive critical patches and security fixes. Red Hat details their lifecycle here, but it boils down to seven years of production quality support, and an optional additional three years of basic bug fixes.

For enterprise customers, this is great and a big part of Red Hat’s success. Stability of the platform and a set in stone upgrade schedule gives larger infrastructures the ability to plan ahead. So, what’s in the new RHEL 6 that would tempt existing users to upgrade before the end of the existing lifecycle?

The answer is features. Red Hat has a big advantage with supporting an operating system for so long, but it comes with the disadvantage of always being behind and having old packages in the repositories. Sometimes Red Hat can push these out with a point release, but sometimes not. Looking through the release notes of RHEL 6, I can see quite a few line items that look tempting:

• ext4 filesystem: much, much faster
• NFSv4: Wow… finally?
• Fuse!
• LVM Snapshot merging: This could potentially be huge, the ability to roll back a change can be a lifesaver in a production environment.
• Fiber Channel over Ethernet: Fiber infrastructure is very expensive, so if you can extend it over Ethernet, this could be a big deal, depending on your infrastructure.
• Memcached 1.4.4
• Ruby 1.8.7 and Rails 3 support
• New configuration tuning daemon, tuned: Looks interesting
• MySQL 5.1
• Windows WHQL-certified drivers: Virtualize Microsoft Windows with Red Hat
• yum history: Finally, a way to undo operations performed with yum
• Samba now supports integration with Windows 2008R2 domains

I’ll be running RHEL 6 in development environments for the next couple of years, making sure that when the time does come for us to upgrade, that we can slide right in. If you are just getting started with Red Hat, I don’t see any reason not to start with RHEL 6. It looks like a great release.