I have 2 HDDs and 5 partitions in them, and I can't find this question answered on DuckDuckGo, Google nor Microsoft; the command doesn't allow to specify a drive letter, so I suppose is for all partitions, but I don't know for sure.

Or the default is C: and I have to change the focus with DiskPart? Windows 8.1 Off and online Help don't have anything about it neither, so I'm lost.


From How NTFS reserves space for its Master File Table (MFT) where it mentions a nearly identical (and identically functioning) registry key at the very bottom of the page:

Note This is a run-time parameter and does not affect the actual format of a volume. Rather, it affects the way NTFS allocates space on all volumes on a given system. Therefore, to be completely effective, the parameter must be in effect from the time that a volume is formatted and throughout the life of the volume. If the registry parameter is adjusted downward or removed, the MFT zone will be reduced accordingly, but this will not have any affect on MFT space already allocated and used.

The parameter simply attempts to ensure that the area after the MFT is kept clear for new entries in the event that the MFT needs to grow. It is essentially an indicator to the system that says "the user reckons they'll have millions of files and we will need MFT entries for a lot more than usual".

It is not a parameter that can be used to increase the MFT size per disk partition.

They do list the command dir /a $mft to show the actual MFT size, but it does not work for me. Edit(by saultube 28): because it's for NT 4.0 which is pre-Windows 2000.

Microsoft do have a tool to show NTFS information per drive NTFSInfo and it will apparently show MFT size.

NTFSInfo will tell you where on the disk the MFT-Zone is located and what percentage of the drive is reserved for it.

In order to simply expand the MFT you can create a massive tree of folders which will use up entries in the MFT forcing it to allocate a new block. Done on an otherwise empty drive this will quickly expand the MFT without actually putting any significant data on the drive. The folders can then be deleted.

There is a tool to do this at Schooltechnician.co.uk: Increasing the size of your MFT but I make no claims about the tool, I am not affiliated and this is simply one I found at a quick search.

Per that page:

In my work, I have servers which hold millions of tiny files. I needed to have a large Master File Table from the outset to prevent future problems. I’ve created a free .Net application that will create a hierarchy of nested folders on a drive, and delete them again when finished. Creating folders seems is the easiest method of artificially causing the Master File Table to grow. Each folder seems to creates a 1024kb entry (1GB of MFT = 1,024,000 folders or files).

  • I knew most of these, I didn't clarify that nor how specific my question should have been; I apologize for that. What I actually wanted to know is how to address the configuration of each partition MFT. I use PerfectDisk for defrag, that on Analysis tells you the size of the MFT, on some mftzone 2 (multiples of 200 MB) is justified, on others only 1, the default is 0 which on which translates in practice to 1. So I guess as I wrote so kindly, it's 1 config fits all unfortunately. Can't give you an up vote for that dumb rule of 15 reputation, this should like Reddit, anyway thanks a bunch!
    – saultube28
    Feb 17 '20 at 11:54
  • BTW good job on the link, search engines these days are so filtered that is getting harder to get good results. That Dir command is for NT 4.0 which is Windows 2000
    – saultube28
    Feb 17 '20 at 11:57
  • I had wondered if you were wanting to configure the MFT, but I wasn't able to find any information on how to go about increasing it above whatever NTFS.sys considers "standard" except by kludges that simply create swathes of folders and deletes them after in order to force it to grow that way. The only documentation I could find that was reasonably authoritative was what I linked. It seems that optimising this particular filesystem area isn't really looked at any more, possibly as on larger volumes the initial "percentage allocated" is large enough that it isn't a problem.
    – Mokubai
    Feb 17 '20 at 12:37
  • Clarification: I made a mistake: Windows NT 4.0 is not Windows 2000, I can't edit the comment, anyway Nt 4.0 which was a lot let restrictive apparently. Windows 2000 is NT 5.0
    – saultube28
    Feb 17 '20 at 13:02
  • 1
    Fragmentation can be bad, but the question is how bad. Is this a real problem you are having and need a solution for? If so then you may need to ask a new question detailing the actual problem you are having and why you need to fix or set the MFT size. If you have a clean drive and just want to bloat the MFT then there is a tool at schooltechnician.co.uk/increasing-the-size-of-your-mft I have also added it to my answer.
    – Mokubai
    Feb 17 '20 at 16:49

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