“Out of sight, out of mind” can be an interesting phenomenon. An example of this is a large piece of furniture, such as an armoire, that’s been standing in a hallway for years and causing people to curse and move around it, or bumps their toes or their heads as they rushed by. Finally someone in the household gets fed up and has the armoire moved out of the hallway and into the garage. Problem solved!
Or is it? Just because that bulky armoire has been moved doesn’t mean it isn’t taking up the exact same amount of space; it’s just doing it somewhere else. Someday in the not-too-distant future somebody’s going to get mad because they’ve been having trouble getting the car into the garage and probably yell at the person who moved the armoire there. It’s still causing the same problem!
In the computer world, file fragmentation has always been a serious problem needing to be constantly addressed. When it comes to servers, fragmentation becomes much more of a problem simply due to the high number of files being created, modified and deleted by multiple users. Fragmentation not only increases dramatically but it also impacts a wider number of people and their production.
SAN was seen as a brilliant way to move much of this traffic off of servers, which it was and is. Because stored data does not reside directly on any of those servers, server power is now used strictly for business applications and network capacity is freed up for other purposes.
But a SAN still consists of disk drives. Fragmentation is still very much a performance-crippling problem on those drives, and (in a similar way to that armoire) just because it got moved off the network does not mean that it isn’t there. In fact, because there are additional steps to requesting and accessing files from a SAN, fragmentation can even have more of an impact from the SAN than from a local or server drive. For further details, see this white paper.
The only way to fully utilize the full benefit of a SAN is with the completely automatic defrag provided by Diskeeper with InvisiTasking. Utilizing otherwise-idle resources, defragmentation occurs whenever and wherever possible so that performance is constantly maintained, and there is never a negative performance impact from defrag. Scheduling is never required.
With Diskeeper, fragmentation is completely removed as a problem, and the SAN solution truly works as it intended. Unlike the armoire in the garage, it is completely gone.