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Point/Counterpoint - /opt vs. /usr/local

Issue 191

From Issue #191
March 2010

May 01, 2010  By Kyle Rankin and Bill Childers
 in
Should a sysadmin put additional software in /usr/local or /opt? Bill and Kyle argue the one true location for third-party software.
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Kyle Rankin is a systems architect; and the author of DevOps Troubleshooting, The Official Ubuntu Server Book, Knoppix Hacks, Knoppix Pocket Reference, Linux Multimedia Hacks, and Ubuntu Hacks.

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/opt or /usr/local

Jeffrey Moncrieff's picture
Submitted by Jeffrey Moncrieff (not verified) on Fri, 10/08/2010 - 18:30.

I usually put small type of applications in /usr/local like clients types applications and servers type applications in /opt. /opt could possible be a nfs or samba mount which makes disaster recovery more easier of that mount. Now having said that you would want to make sure that share was located on a system that has a redundant backups ie RAID.

What about /srv vs. /var/lib ?

Anonymous's picture
Submitted by Anonymous (not verified) on Sat, 08/21/2010 - 05:01.

... and /home vs. /usr/home ? And /usr vs. /usr/local ?

An alternative view point just to mix it up.

Mike.Tiernan's picture
Submitted by Mike.Tiernan on Sun, 04/18/2010 - 08:50.

I agree with both Bill and Kyle in their discussion of /opt vs. /usr/local (if such a thing is allowed) but I have yet another take on it given to me by some of the brains I used to work with who had a keener grasp of the idea of multiple computers vs single standalones.

If I am running a system as a standalone machine (even if it is networked to others of it's ilk) but shares no common data/code then /opt is a symlink to /usr/local

However, if I have a set of systems that have locally unique files, they, as Kyle said, go in /usr/local but the packages/tools/files that I build in one place to make available to all the systems in my "cluster" (not cluster computing, just grouped) then all these files and things go into /opt which is a shared mount point as Bill discussed.

And, if you are really good, you'll have /opt for different flavors of systems, such as opt.x86_64, opt.i386, opt.sol9, opt.irix, etc. and they automount as needed.

A simplistic example of the difference would be something like this:
Say you have four Linux hosts, one in Buffalo, one in Boston, and two in the central office in Dallas. The weather data from each of the sites is automatically stored in a data file in /usr/local because two of the three sites don't need to know about the data for the remotes. The program which reads this data, is the same binary and is found in /opt on each machine. Each of the systems can generate the local data trending information and store it in /usr/local but none of the systems can write to /opt.

Yes, it's a contrived example but I hope it illustrates the point reasonably well.

Does the use of a "formal" packaging system such as RPM or DEB change this? No, it just makes it different.

So, in closing, in my opinion, it's a draw!

(If any sysadmin counts the six extra characters in /usr/local as an impediment to their job, they should be hanging it up right now. I question if any decent sysadmin can even measure the difference in time between typing /opt and typing /usr/local it is so small.)

Thanks for all the conversations!

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