dealing with large disk arrays

[defrag convert]

Hi,
I now manage a server with multiple large disk arrays (about 400GB each) & have fast moving data being written to them  constantly & then deleted daily (full turnaround approx 150GB /week). Currently the arrays are heavily fragmented both for both files & folders.

I've tried defragmenting them but, with the nature of the data transferring, it just fails (or crashes the server.... ).

Is there any way to utilise the "Flash Memory Disk" option to just defragment the free space in the hope the files will become less fragmented?

[Darlis]

The Flash Memory Disk script first defragments the files and then the free space. You can make it defrag the free space only if you edit the script and put "#" just before "Defragment(Fast)".

Optimizing a live system is difficult. Can you disconnect the server for a few hours for maintenance?

I may help if you set the value for FileMoveChunkSize to "50MB" (edit the Settings.MyD file). This reduces the time MyDefrag locks a file and can thus be used by other programs again.

[jeroen]

I've tried defragmenting them but, with the nature of the data transferring, it just fails (or crashes the server.... ).

Can you expand on that? I built the first versions of MyDefrag because I had a need for an automatic defragger for servers. In other words, MyDefrag is specifically designed to be used on fully operational machines, i.e. servers. It should not "fail" or "crash the server". If you have a problem then see the I have a problem! page for instructions on how to make a debug logfile.

Is there any way to utilise the "Flash Memory Disk" option to just defragment the free space in the hope the files will become less fragmented?

You could make a change to the FlashMemoryDisk script as Darlis has pointed out. But I doubt very much that your problem will go away if you do that, whatever problem you are having.

[Kasuha]

My experience is, using MyDefrag on busy disk leads to MyDefrag often wrapping moved files around currently unmovable open file fragments and later considering them fragmented again after that file is released. The bigger the file, the greater the chance of this happening. This is not bad, the file is still "almost defragmented" and can be used in this state without problems. It just keeps looking bad and MyDefrag will try to defragment it again when you give it chance.

Another fact is, FastFill does not work very well if run on fragmented zone. When filling gaps it always uses whole files, not just fragments lying above the filled area - so it fills gaps between fragments and then uses these fragments to fill other gaps, creating new gaps in already filled area without returning to them. Also, FastFill has tendency to "shake" small files down leaving large files in the end reducing its further chances to fill gaps.

Personally I'd recommend you to exclude all large files in the first step and only try to both defragment and fastfill all files below certain limit such as 50 MB. If you succeed with that you can try to extend the file size limit and try the same with larger files. This could gradually defragment both files and free space on your disks.