Terminal says 'unknownf81edfe49998' Huh?

Question

I've been doing some research into defragging on a Mac. Mixed info about it. It seems that it depends on the kind of user you are.
Nice article here http://bit.ly/OSX_defrag with some interesting advice at bottom
+you can simply open the Terminal and type: ’sudo periodic daily weekly monthly’ followed by Return, enter your Administrator password, and OS X will take care of things for you. If your Mac is left on all the time, then the operating system will run these processes automatically in the early hours of the morning.+
Worth knowing.
However when I did it I got this message 'unknownf81edfe49998'
Searched on the net for it with no result. So is that good or bad???
And any thoughts on that article? Or has this subject been done to death here?
Cheers!

Answer 1

Os X does a good job of defragmenting its own System files (under 20MB), but it pretty much
leaves Large files, data files, user files and freespace to fend for itself.
Obviously a heavy photoshop, web developer, music and/or video editing user would make a mess
of large files and freespace and would need a defragmenting solution.
http://www.macattorney.com/ts.html#6
One of the simplest defragmenters comes with OS X: Time Machine. Restoring a Time Machine
backup will put everything right back where it is supposed to be. Usually takes less time than
doing a full defragmentation with with a defrag utility, especially if all System/Data files reside
on a single volume.
I own iDefrag and I love it. I seldom do full defrags with it though. I use the "single file" defrag
option a lot. Usually only a few files get badly defragmented, so I defrag the bad ones and ignore
the rest. On a regular basis, my Safari cache and my mail are the worst offenders. I set iDefrag
to simply delete the Safari cache and tmp files when I run it instead of defragging them.
Large user files many times fragment badly too.
When free space gets badly fragmented, I use the optimize setting in iDefrag, or if it is a
data drive I simply use the compact setting. Occasionally, I will defrag metadata.
On my Mac Pro, my data is kept on separate volumes on separate drives, this keeps
boot volume fragmentation minimal. My User account is on the boot drive and I often have large
video or other data files on my desktop, but I move them to another drive as soon as they are
completed. For convenience, some of my data folders are symlinked to data folders on other
volumes, such as mail, iTunes and work documents.
Keeping your volumes healthy using Disk Warrior and Disk Utility in conjunction with proper
and sensible defragmentation, will help keep performance optimal.
I never have a need to reinstall, nor would I gain anything by reinstalling as long as I am following
the above rules.
I use iDefrag on my data volumes more than my boot volume. One especially useful task is
defragmenting files on sparse bundle disk images with it. After I defrag (files only) on the
sparse bundle, I compact it with hdiutil. No wasted space.