Intro Download and install Frequently Asked Questions Tips and tricks

Homepage







© J.C. Kessels 2009
MyDefrag Forum
July 25, 2014, 07:47:16 am *
Welcome, Guest. Please login or register.

Login with username, password and session length
News:
 
   Home   Help Search Login Register  
Pages: [1]
  Print  
Author Topic: Compact and truncate MFT  (Read 6573 times)
BloodySword
Global Moderator
JkDefrag Hero
*****
Posts: 1158



View Profile
« on: January 14, 2010, 11:39:16 am »

Paragon Total Defrag ( http://www.paragon-software.com/home/total-defrag/) has a Compact & truncate MFT feature. What do you think of it? Would it be possible for MyDefrag? Would it be save? (crash / power failue)
Logged

Greetings from Germany!
quanthero
JkDefrag Hero
*****
Posts: 234



View Profile
« Reply #1 on: January 14, 2010, 12:30:35 pm »

I tried this feature in PTD a long time ago when, for some weird reason, my MFT was like 1GB and only 10% of it was occupied. Everything worked well.

However, I think implementing this in MyDefrag will be too complicated and time consuming. First of all, MFT cannot be compacted and truncated while Windows is running, so some kind of pre-boot module is required. Secondly, the program has to do it 'manually' (i.e. there are no API calls in Windows which can accomplish that, etc.), so programming involved in developing such feature is certainly complicated and time-consuming. But this is just my opinion. It would be interesting to know what are Jeroen's thoughts on this idea.
Logged
BloodySword
Global Moderator
JkDefrag Hero
*****
Posts: 1158



View Profile
« Reply #2 on: January 14, 2010, 12:40:47 pm »

Yes but this feature would be quite interesting. I would like to test it with a usb stik formatted with NTFS. Adding and deleting files and watching the MFT occupiation and testing how MyDefrag is able to optimize this and see if there are problems or MFT corruption.
Logged

Greetings from Germany!
jeroen
Administrator
JkDefrag Hero
*****
Posts: 7205



View Profile WWW
« Reply #3 on: January 14, 2010, 01:30:28 pm »

I agree that it would be a useful feature. But as quanthero has already said it would be difficult to build. And it would be dangerous. Microsoft has published the structure of FAT, but not of NTFS. There is a lot of reverse-engineered information on the internet, enough for me to have build the MFT scanner in MyDefrag, but not enough to even think about shrinking the MFT.
Logged
BloodySword
Global Moderator
JkDefrag Hero
*****
Posts: 1158



View Profile
« Reply #4 on: January 14, 2010, 01:39:20 pm »

When MyDefrag would be open source, perhaps there are some programmers wich would test such a feature. Why is MyDefrag closed source?
Logged

Greetings from Germany!
Kasuha
JkDefrag Hero
*****
Posts: 595


View Profile
« Reply #5 on: January 14, 2010, 05:26:13 pm »

If I remember it correctly, jkDefrag was open source and Jeroen expected that a developer community will grow around it but it did not happen, instead other defragger authors started using parts of jkDefrag code in their (paid) products.

My opinion regarding MFT internal optimization is, unless Microsoft publishes API functions for it, MyDefrag should leave it as is. I also think that for majority of people MFT size and fill factor is not an issue.
« Last Edit: January 14, 2010, 05:31:55 pm by Kasuha » Logged
Leolo
JkDefrag Hero
*****
Posts: 98


View Profile
« Reply #6 on: October 05, 2010, 11:08:01 pm »

Does anyone know what exactly is this "compact and truncate" feature?

The closest thing to a description I could find is this:

http://support.microsoft.com/kb/814594
Quote
NTFS Master File Table (MFT) Expansion
When an NTFS volume is created and formatted, NTFS metafiles are created. One of these metafiles is named the Master File Table (MFT). It is very small when it is created (approximately 16 KB), but it grows as files and folders are created on the volume. When a file is created, it is entered in the MFT as a File Record Segment (FRS). The FRS is always 1024 bytes (1 KB). As files are added to the volume, the MFT grows. However, when files are deleted, the associated FRSs are marked as free for reuse, but the total FRSs and associated MFT allocation remains. That is why you do not regain the space used by the MFT after you delete a large number of files. Currently, only third-party defragmenters consolidate unused MFT FRS records and reclaim unused MFT allocated space.

Is that what Paragon refers to as "compact and truncate"?
Logged
jonib
JkDefrag Hero
*****
Posts: 822


View Profile
« Reply #7 on: October 06, 2010, 01:20:03 am »

Is that what Paragon refers to as "compact and truncate"?
Yes.

jonib
Logged

Pages: [1]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.5 | SMF © 2006-2008, Simple Machines LLC Valid XHTML 1.0! Valid CSS!