Thursday, March 31, 2011

Not all defragging engines are equal

I've written about this before, but it has come up a couple of times this week - Not all defraggers are the same.
Some are free, some cost money, some have very intelligent algorithms, some aren't so good. Tweaking and optimising a defragging algorithm takes time. Time typically has a cost associated with it.
One thing we've learnt over the last three years is that Domino places some rather unique requirements on a defragmention algorithm. The following rules seem to always apply:
  • the longer the server has been running, the worse state it is in.
  • available freespace is likely to be highly fragmented.
  • it is not unusual to have highly fragmented multi gigabyte database. As a rule, multi gigabyte files (30GB+) outside of Domino are fairly uncommon.
  • it is difficult to defrag files that are constantly changing.
In an environment where you have a lot of small databases with a lot of disk space available, the job of a defrag engine is rather easy.
As you move up the scale, and enter the real world of Domino it gets harder and harder, and the algorithm used by the defrag engine needs to be smarter.
I've been asked a number of times, why not just use the 'Free stuff'. Free defragging products typical are:
  • not designed from the ground-up to meet the needs I outlined above.
  • perform relatively simple cluster moves.
  • do not handle multi-gigabyte, constaintly changing files very well.
  • are a simple wrapper around a freeware utility that falls in one of the categories above.
I'm not saying they are bad, or don't work, but what I will say is this - developing a Domino specific defragging engine has been challenging, very time consuming and costly.
Which brings up a well known idiom, "You get what you pay for"
Given all this, we are please to announce the availability of Defrag.NSF version 2.06. We have done a significant amount of fine-tuning to the defragging engines for this update and we are excited about the results we're obtaining.
Put Defrag.NSF to work on your servers today with a 30 day, supported Free Trial and see for yourself. Register here

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