MFT and Reserved Zone?

[jeroen]

Let's say the MFT ends at Cluster 1000. The NTFS reserved area goes from 1000 to 3000.
If I want to add a gap with 1000 Clusters, the next files will be placed at Cluster 4000?

Yes.

I thought that MyDefrag will first try to put files at Cluster 2000, if possible. 

No, the gap will be placed after the NTFS reserved area.

[WindHydra]

I tested the PlaceNtfsSystemFiles with $mft and regular files to see how the MFT reserved zone changes when you move files into it.  The patterns are:

If you move the $mft and there is space available right after $mft:
The reserved zone is recreated right after $mft until 12.5% (Windows default) or until the first file it encounters.

If the reserved zone is right after $mft:
When you move a random file into the reserved zone, the reserved zone is chopped by that file.  So if the reserved zone is 12.5% and you moved a file 1% into the reserve, the reserved zone will only be 1% after you dismount the volume.

If the reserved zone is NOT right after the $mft (as when using the default script):
When a file is moved into the reserved zone, the reserved zone is recreated somewhere else, with the default size of 12.5%. (didn't try with a disk with no 12.5% gap available yet)


With these observations, I would like to request a new Settings to allow us to treat the mft reserved zone as free space (something like IgnoreMFTReservedSpace()?) so we can move files into it and reduce its size without the need to specify an absolute position

The code I used is attached.

[jeroen]

I am sorry, but your script always places files in regular disk space, not in the NTFS reserved area. The makegap() action will always set the beginning of the next zone in regular disk space.

[WindHydra]

I am sorry, but your script always places files in regular disk space, not in the NTFS reserved area. The makegap() action will always set the beginning of the next zone in regular disk space.

If you use a set position on disk (like untilpercentageofvolume) it can move files into the reserved zone.  Screenshots attached.

First one is after moving $mft untilpercentageofvolume(60) then dismount.
2nd one is moving "circle of life.flv" untilpercentageofvolume(65), before dismount.
3nd one is after dismount.

[jeroen]

Thanks for your tests, I appreciate it. I will do some tests myself and see if it is possible the completely ignore the NTFS reserved area. I tested this a long time ago when I was developing JkDefrag, but Microsoft have since then made some changes to the area. A couple of weeks ago I tested with special NTFS files, which led to the PlaceNtfsSystemFiles() fileaction, but I think I did not test with regular files.

[amk]

Use not AddGap(Megabytes()) but AddGap(UntilMegabytes()). This must not create gap after reserved area.

[HolyMan]

Let's say the MFT ends at Cluster 1000. The NTFS reserved area goes from 1000 to 3000.
If I want to add a gap with 1000 Clusters, the next files will be placed at Cluster 4000?

Yes.

I thought that MyDefrag will first try to put files at Cluster 2000, if possible. 

No, the gap will be placed after the NTFS reserved area.

After restart the NTFS reserved zone will then be extended into the newly created free space. When you run the same script again the gap will be increased again, After restart turned to NTFS reserved area, which causes the gap to be increased at next run, etc.
I would rather see that different. I think it would be better if the NTFS zone was treated like normal free space when making a gap.

Good that I read it now. I was just optimizing a disk with the sequence:

Code:

Debug(0)
  FileSelect
    filename("$mft")
  FileActions
    SortByName(Ascending)
  FileEnd

  MakeGap(Megabytes(1))
  MakeGap(UntilMegabytesMultiple(10))

And observed that the gap increased 10 MB after restart. I don't want that, so next run I will have to change this and put in a fixed start for the next zone.

In reading this thread further I see this was allready picked up. Great.

[WindHydra]

Just found out that in order to move files into the MFT reserved zone, the MakeGap zone must be the first zone.  Just in case someone can't get it working.

[Henno]

Could you let us show the script that does that?

Regards, Henno.

[HolyMan]

Just found out that in order to move files into the MFT reserved zone, the MakeGap zone must be the first zone.  Just in case someone can't get it working.

This sounds like a very convenient bug in the MS defrag API.

[DIRTY_DEALER]

I move it when I need to....

1: defrag first
2: use cachemanxp to increase the reserved area
3: reboot

zone has moved 

4: defrag again
5: use cachemanxp to return the reserved area to normal
6: reboot again
7: enjoy the new layout   

[eejay]

I use MyDefrag and UltimateDefrag 2008, the latter has a great facility for placing system files anywhere you want on disc.
Otherwise, it's not as flexible as MyDefrag.
I've excluded system files and directories from MyDefrag and let Ultimate Defrag handle these.
So, directories are placed next to MFT followed by the usual $ files, pagefile, hiber file and the journal at the end (it does not defragment when placed here). This whole string of files is placed in from the start of the disc, maybe 5% in.
This way, I find, the system files generally do not fragment, maybe because they are kept apart from the usual files.
I do not notice any degradation of performance - if anything, booting appears to be faster.
Maybe a bit unconventional but it works for me.