Defrag, Diskeeper, and white space

  • Thread starter Thread starter Obewahn
  • Start date Start date
O

Obewahn

I'm confused. My Diskeeper works great when I've got > 20% free space
(thought it never seems to consolidate free space) so I'm wondering why.
I've also heard that about 12% of the logical drive is reserved for
the MFT though that number can and does change. Can someone give me a
link to a white paper on that one?

Thanks all,

Cheers
 
Hi -

Here's an article on the Microsoft KB that gives some info on the MFT.
Don't know if it answers your specific questions, but it might get you
started in the right direction.

http://support.microsoft.com/default.aspx?scid=kb;en-us;174619&Product=win2000

As to why Diskeeper doesn't necessarily consolidate all the free
space, the short answer is that our research shows it is an
unnecessary use of system resources to achieve no measurable system
performance gain. In other words, it doesn't improve performance, so
why burn up the resources? That said, the free space consolidation in
version 8.0 has been improved. If you're using an older version, I'd
suggest checking out the newest one. (It has a number of other new
things, too.)

I hope this helps -

Vaughn McMillan
Executive Software
 
Diskeeper isn't really designed to consolidate free space. It does have an
Improved Free Space consolidation mode, but it's not really effective. They
seem to feel that free space consolidation doesn't do much to improve
performance - which from a file read perspective makes sense -f rom a write
perspective it doesn't. However, what free space consolidation does gain
you is the ability for the file system to create new files contiguously
(they are not immediately created fragmented). In addition, if the free
space is highly fragmented it can cause slow down in new file creation.
Allowing new files to be created contiguously also means that you don't have
to defrag as often :)

The MFT Reserved Zone size can flucuate because under Windows 2000 the MFT
Reserved Zone is dynamically created every time the drive is mounted. By
default, it is 12.5% of the drive but it can be less if the file system
decides to store files inside of the Reserved Zone (it will try to avoid
this unless you get into a low free space condition). Under NT4, it is
always 12.5% of the drive.

- Greg/Raxco Software
Microsoft MVP - Windows Storage Management/File System

Disclaimer: I work for Raxco Software, the maker of PerfectDisk - a
commercial defrag utility, as a systems engineer in the support department.
 
The MFT Reserved Zone size can flucuate because under Windows 2000 the MFT
Reserved Zone is dynamically created every time the drive is mounted. By
default, it is 12.5% of the drive but it can be less if the file system
decides to store files inside of the Reserved Zone (it will try to avoid
this unless you get into a low free space condition). Under NT4, it is
always 12.5% of the drive.
Click to expand...

I understand that this isn't quite the right group for this question,
but how about WinXP? I have a 40gb system drive. It has 77% free
space. Yet, suddenly, with no unusual changes at all, the MFT
reserved dropped to maybe 15% of what it was a couple of days ago. Is
this normal, or does it signal a potential problem?

Thanks,

JM
 
Jose,

The Reserved Zone acts the same way under Windows XP as it does under
Windows 2000 - it is dynamically created every time the drive is mounted.
The big difference is that with Windows XP, the free space inside of the
Reserved Zone can be used by defragmentes. Under Windows 2000, it can't.

This doesn't signify that there is a potential problem - just that the file
system for some reason but a file inside of the Reserved Zone and when you
rebooted your system, the Reserved Zone shrunk.

- Greg/Raxco Software
Microsoft MVP - Windows Storage Management/File System

Disclaimer: I work for Raxco Software, the maker of PerfectDisk - a
commercial defrag utility, as a systems engineer in the support department.
 
Back
Top