Managing the Master File Table

[chrisjbo]

We have 4 PC's at home, and my PC has the diskeeper and I think it is an excellent software. However, I am only licensed for one PC and I have intsalled the Piriform Degfaggler into the other PCs, as I think that the Windows defragmenter is not 100%. The latest Diskeeper also slows down my older PC (Pentium 3) and the Degfraggler software is what I needed!

 

Now with the Diskeeper, it manages the MFT. When I have done the defragmentation, I refer to the 'Job report' and it advises on the state of the drive after defragmentation. Most times, the report is satisfactory, but sometimes it warns that the MFT is full and becomes fragmented, and I set it to extend the MFT capacity, and Diskeeper shows the 'padding' progress. The Master File Table is a bit like a Phonebook, it contains the details of all files held on our system. Like a address book it is much cheaper to do a lookup on the MFT for files than scan our HDD.

 

It is known that a fregmented drive slows down the PC, but having a defragmented drive with the MFT that is full or fragmented limits the PC's top performance. (Correct me if I'm wrong).

 

In conclusion, I would like to see the Piriform Defraggler software to have the capability to manage the MFT as well, and I hope that the developers at Piriform will look into it.

[Augeas]

NTFS manages the MFT, and the idea of defragging the internals or reducing the size is so scary that even M/S doesn't try to do it. Non-contiguous allocations of the MFT can be made contiguous but the size is not reduced nor are empty slots removed.

 

In XP the MFT will only have non-contiguous allocations if either the disk is around 90% full or if a very large number of files are being created (in excess of millions). In Vista it's different as non-contiguous mft allocations are how it's designed.

 

What O/S are you on? I would be interested to know how Diskeeper extends MFT capacity.

[chrisjbo]

NTFS manages the MFT, and the idea of defragging the internals or reducing the size is so scary that even M/S doesn't try to do it. Non-contiguous allocations of the MFT can be made contiguous but the size is not reduced nor are empty slots removed.

 

In XP the MFT will only have non-contiguous allocations if either the disk is around 90% full or if a very large number of files are being created (in excess of millions). In Vista it's different as non-contiguous mft allocations are how it's designed.

 

What O/S are you on? I would be interested to know how Diskeeper extends MFT capacity.

 

I'm using the Windows XP Home Edition and Diskeeper version 10.0.608.0

See images of what it looks like...

 

 

 

 

[Augeas]

Trying to find out who does what to the MFT in whatever version of NTFS makes my head hurt.

 

At a guess, what's happening with Diskeeper (trying to keep what it's showing in line with what M/S says NTFS does) is that it's reporting on the current size usage of the MFT, as (in Juke Box) 1200 entries and 92% full. In XP 12.5% of the disk space is 'allocated' as the MFT zone for use by the MFT, which would be 1.2 gb. The initial allocation of the MFT however is far smaller than that, in this case just over 1 mb.

 

In normal use the MFT will simply expand by allocating an additional contiguous area in the MFT zone. Although the MFT now has 3 fragments (first 16 records, first allocation, second allocation) it is not fragmented in the sense of having separate elements dispersed across the disk, and defragging would neither affect or enhance it.

 

Perhaps Diskeeper is simply allocating and deleting a number of small files to expand the MFT to the parameter specified. This will just do exactly the same thing as NTFS would do in normal use. The only advantage I can see of preallocating MFT entries is if the disk is likely to be filled to capacity with large files, thus forcing files into the MFT zone and causing the MFT to fragment when it is subsequently extended.

 

It's interesting that Diskeeper allows the MFT to be 'padded' to approx 25% of the volume size, which is twice the default MFT zone size.

 

Now my head does hurt.