MFT reserved area causing MFT fragmentation

[poutnik]

It is funny to observe, that MFT reserved area causes MFT fragmentation,
forcing it to wrap around it by sorting action. ( I do not have MFT at start ).

No problem, just funny.
I wonder, why MS does not allow to put MFT inside ?   

[WindHydra]

I think it's the sorting action that causes the fragmentation, not the reserved zone.  If you do not move the MFT, it will grow into the reserved zone.  MyDefrag can move the part of MFT that might be in the reserved zone out of the reserved zone but can't put it back in, so the MFT ends up warped.

[poutnik]

For sure it is as you have said, for obvious reason,
sorting takes MFT reserved zone as unmovable area, aligning MFT across.
But this was not any surprise.

The only thing I do not understand is ,
 
when MS invented MFT reserved zone to prevent MFT fragmentation,
why they does not allow MFT to be put inside, while movable ?

[jeroen]

At the moment MyDefrag does not try to put the MFT in the reserved area, and will always wrap around. I have it on my list to look if maybe the API allows the MFT to be moved into the reserved area.

[ToolmakerSteve]

At the moment MyDefrag does not try to put the MFT in the reserved area, and will always wrap around. I have it on my list to look if maybe the API allows the MFT to be moved into the reserved area.

If anyone comes across any solution to how to get that reserved area to be in a different location, I would love that. Even if I have to reformat the drive to do it.

Its crazy that on a large disk, it is sitting squarely in the prime area, covering 12.5% of the fastest end of the disk.

Don't know if Vista's disk formatter does any better, but XP leaves a gap before it that isn't big enough to be useful for my purposes -- but is big enough to be annoying to waste. In the interests of minimizing head movement, I'm thinking of putting boot files there, then filling the rest with a dummy file. Then put the MFT just AFTER the (wasted) reserve area, then the dirs, then small files, then a gap for new files, etc.

I hate to waste the fastest part of the disk, but I believe it is more important to keep head movement within a narrow range during most accesses. Hence my thinking "MFT + dirs + small files + new file gap" all together.

UPDATE:
For now decided to accept the swing across 12.5% of the disk, to allow XP to use the MFT reserve area as it expects (to expand the MFT).

So I manually calculate how far in the MFT is, put the DIRS a bit before that (at a position which I will need to adjust as the DIRS grow).

Maybe I'll even try to stuff really small files into the area before the DIRS.

~TMSteve

[jeroen]

If anyone comes across any solution to how to get that reserved area to be in a different location, I would love that.

People have reported that after MyDefrag has moved the MFT and after a reboot, that Windows somehow reassigns the reserved area. It's then a lot smaller.

[ToolmakerSteve]

People have reported that after MyDefrag has moved the MFT and after a reboot, that Windows somehow reassigns the reserved area. It's then a lot smaller.

Thanks for that tip!  I reformatted a disk, and did some experimentation, with reboots.

Here is what I found:

After a reboot, the area reported as reserved extends from the current MFT position to the next obstacle (or to the percentage stated by the Reg key: 12.5% for the default "1" key value).

Therefore, on a near empty disk, with at most two reboots, it is possible to get an MFT and a Reserved Area of any desired location and length. It took me two boots, because I was trying to place MFT in middle of its original reserved area, with a file to act as an obstacle a fixed distance beyond it.

This is neat!


NOTE: I don't know whether ReclaimMFTzone would try to move the obstacle file I placed farther away; I removed that line from my scripts just in case.

[WindHydra]

If the drive is not the boot drive, you can just use something like "chkdsk d: /x" to dismount the drive in command prompt, then just cancel the scan by closing the command prompt window, and the mft reserved zone will be reallocated.

If $MFT grows into the reserved zone, ReclaimMFTzone moves $MFT out So I removed that line too.

[jeroen]

If the drive is not the boot drive, you can just use something like "chkdsk d: /x" to dismount the drive in command prompt, then just cancel the scan by closing the command prompt window, and the mft reserved zone will be reallocated.

An easier way to dismount a volume is with "fsutil volume dismount d:".

p.s. Dismounting only works on NTFS volumes, not FAT volumes.
p.s. Volumes are automatically remounted by Windows.

[jonib]

An easier way to dismount a volume is with "fsutil volume dismount d:"

Interesting, I use Contig to create a big file that almost fills the volume I need to get rid of the MFT reserved area from and then delete it, now the reserved areas are gone until reboot, "fsutil volume dismount d:" is nice for the volumes that can be dismounted, thanks for the tip.

jonib