"Reserved for MFT"?

"John John (MVP)" wrote in message

> Jim wrote:
>
>> While defragging my C: drive, there is a pretty large sector
>> saying Reserved For MFT. Can anyone explain just what
>> that space is needed for?
>
> It's reserved space for the Master File Table. The MFT is one of the most
> important files on your hard disk, each file on the disk is recorded in
> the MFT, the operating system uses the MFT to find your files and to
> record information about the files.
>
> Because MFT fragmentation can degrade performance the file system
> preemptively reserves a large contiguous block for the MFT when the
> drive is formatted. This space isn't lost, it will be used if needed. If
> the disk runs out of space for files the file system will relent and
> yield space for the files from the MFT zone. The opposite is also true,
> if the MFT zone fills up it will take space from the available (free)
> disk space for its needs, the problem there is that in both instances
> the MFT will become fragmented and the built in disk defragmenter will
> not be able to defragment it. Also note that small files of 1KB or less
> are stored in the MFT.
>
> John

Just curious here. I used diskeeper version 8. There is no designation for
MFT usage area in the graphical representaton of the XP windows partition.
There is an area called "reserved system", and yet another for the swapfile
itself.

On one PC, the reserved system area is small, 17GB partition. On another
PC, the reserved system area is comparatively large, about ten times bigger
graphically, swapfile is about the same size, 26GB partition. The latter
sees little changes, very little internet, few MS updates, mostly one game
usage is all it sees most of the time. The former is used alot on the
internet, this one I'm using now, has all MS updates, Office usage when on
and offline. Both are NTFS version 3.1 of course. Why the disparity?
--
Dave
 >> Stay informed about: ""Reserved for MFT""? 

....

Also note that small
> files of 1KB or less are stored in the MFT.

That caught my eye: Do you mean the files stored there are 1k, or that
any 1k file could be stored there?
Not making sense to me.

Twayne
 >> Stay informed about: ""Reserved for MFT""? 

Twayne

Paragraph 4 in the link covers your question;
http://www.pcguide.com/ref/hdd/file/ntfs/archMFT-c.html

--



Hope this helps.

Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~

Twayne wrote:
> ...
>
> Also note that small
>> files of 1KB or less are stored in the MFT.
>
> That caught my eye: Do you mean the files stored there are 1k, or
> that any 1k file could be stored there?
> Not making sense to me.
>
> Twayne
 >> Stay informed about: ""Reserved for MFT""? 

John

I am not sure I can reconcile your last paragraph with this extract from
KB 227463

In Windows 2000, it does not defragment NTFS metadata files, such as the
Master File Table (MFT), or the metadata that describes a directory's
contents. This limitation has been removed in Windows XP and later. It
cannot defragment encrypted files in Windows 2000. This limitation has
been removed in Windows XP and later.
Disk Defragmenter Limitations in Windows 2000, Windows XP, and Windows
Server 2003
http://support.microsoft.com/kb/227463


~~~~


Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~


John John (MVP) wrote:
> Jim wrote:
>
>> While defragging my C: drive, there is a pretty large sector
>> saying Reserved For MFT. Can anyone explain just what
>> that space is needed for?
>
> It's reserved space for the Master File Table. The MFT is one of the
> most important files on your hard disk, each file on the disk is
> recorded in the MFT, the operating system uses the MFT to find your
> files and to record information about the files.
>
> Because MFT fragmentation can degrade performance the file system
> preemptively reserves a large contiguous block for the MFT when the
> drive is formatted. This space isn't lost, it will be used if needed.
> If the disk runs out of space for files the file system will relent
> and yield space for the files from the MFT zone. The opposite is also
> true, if the MFT zone fills up it will take space from the available
> (free) disk space for its needs, the problem there is that in both
> instances the MFT will become fragmented and the built in disk
> defragmenter will not be able to defragment it. Also note that small
> files of 1KB or less are stored in the MFT.
>
> John
 >> Stay informed about: ""Reserved for MFT""? 

Actually there are two things at work on Windows XP. The first one is
that on XP the MFT is apparently just an NTFS-hint, it no longer
reserves large contiguous blocks for the MFT and the defragmenter can
defrag in and out of the MFT. That is the theory... but in practice it
doesn't always work like that. This is still fairly new to me but my
findings have been that there may still be a minimum of 12.5% of the
drive reserved for the MFT zone on Windows XP installations and that
when (if) there is no such large reserved zone (NTFS-hint) the
defragmenter still does not fully defragment the MFT, I have seen it in
two fragments in my test and I can run defrag in GUI or command-line
mode until the cows come home and the MFT is still left in two
fragments. Documentation on this is scant and I haven't done extensive
testing so I don't know what exactly is going on with this. I think
that the differences may be whether the drive is formatted by the XP
setup program or whether it is formatted by an up and running XP
installation. This is just a guess, I haven't had time to do more test
on this. Greg from Raxco could probably shed more light on this but I
haven't seen him in the groups for a little while...

John

Gerry wrote:

> John
>
> I am not sure I can reconcile your last paragraph with this extract from
> KB 227463
>
> In Windows 2000, it does not defragment NTFS metadata files, such as the
> Master File Table (MFT), or the metadata that describes a directory's
> contents. This limitation has been removed in Windows XP and later. It
> cannot defragment encrypted files in Windows 2000. This limitation has
> been removed in Windows XP and later.
> Disk Defragmenter Limitations in Windows 2000, Windows XP, and Windows
> Server 2003
> http://support.microsoft.com/kb/227463
>
>
> ~~~~
>
>
> Gerry
> ~~~~
> FCA
> Stourport, England
> Enquire, plan and execute
> ~~~~~~~~~~~~~~~~~~~
>
>
> John John (MVP) wrote:
>
>>Jim wrote:
>>
>>
>>>While defragging my C: drive, there is a pretty large sector
>>>saying Reserved For MFT. Can anyone explain just what
>>>that space is needed for?
>>
>>It's reserved space for the Master File Table. The MFT is one of the
>>most important files on your hard disk, each file on the disk is
>>recorded in the MFT, the operating system uses the MFT to find your
>>files and to record information about the files.
>>
>>Because MFT fragmentation can degrade performance the file system
>>preemptively reserves a large contiguous block for the MFT when the
>>drive is formatted. This space isn't lost, it will be used if needed.
>>If the disk runs out of space for files the file system will relent
>>and yield space for the files from the MFT zone. The opposite is also
>>true, if the MFT zone fills up it will take space from the available
>>(free) disk space for its needs, the problem there is that in both
>>instances the MFT will become fragmented and the built in disk
>>defragmenter will not be able to defragment it. Also note that small
>>files of 1KB or less are stored in the MFT.
>>
>>John
>
>
>
 >> Stay informed about: ""Reserved for MFT""? 

Lil' Dave wrote:

> "John John (MVP)" wrote in message
>
>
>>Jim wrote:
>>
>>
>>>While defragging my C: drive, there is a pretty large sector
>>>saying Reserved For MFT. Can anyone explain just what
>>>that space is needed for?
>>
>>It's reserved space for the Master File Table. The MFT is one of the most
>>important files on your hard disk, each file on the disk is recorded in
>>the MFT, the operating system uses the MFT to find your files and to
>>record information about the files.
>>
>>Because MFT fragmentation can degrade performance the file system
>>preemptively reserves a large contiguous block for the MFT when the
>>drive is formatted. This space isn't lost, it will be used if needed. If
>>the disk runs out of space for files the file system will relent and
>>yield space for the files from the MFT zone. The opposite is also true,
>>if the MFT zone fills up it will take space from the available (free)
>>disk space for its needs, the problem there is that in both instances
>>the MFT will become fragmented and the built in disk defragmenter will
>>not be able to defragment it. Also note that small files of 1KB or less
>>are stored in the MFT.
>>
>>John
>
>
> Just curious here. I used diskeeper version 8. There is no designation for
> MFT usage area in the graphical representaton of the XP windows partition.
> There is an area called "reserved system", and yet another for the swapfile
> itself.
>
> On one PC, the reserved system area is small, 17GB partition. On another
> PC, the reserved system area is comparatively large, about ten times bigger
> graphically, swapfile is about the same size, 26GB partition. The latter
> sees little changes, very little internet, few MS updates, mostly one game
> usage is all it sees most of the time. The former is used alot on the
> internet, this one I'm using now, has all MS updates, Office usage when on
> and offline. Both are NTFS version 3.1 of course. Why the disparity?

Yes, I have found out about that a little while ago and much like you I
have found this to be inconsistent. One, if unlikely, possibility would
be that the default NtfsMftZoneReservation area would have been changed
in the registry and that one disk would have a larger than 12.5% MFT
zone. But more than likely the explanation here
http://www.diskeeperblog.com/archives/2006/11/the_mystery_of.html
explains your findings.

John
 >> Stay informed about: ""Reserved for MFT""? 

"John John (MVP)" wrote in message

> Lil' Dave wrote:
>
>> "John John (MVP)" wrote in message
>>
>>
>>>Jim wrote:
>>>
>>>
>>>>While defragging my C: drive, there is a pretty large sector
>>>>saying Reserved For MFT. Can anyone explain just what
>>>>that space is needed for?
>>>
>>>It's reserved space for the Master File Table. The MFT is one of the
>>>most important files on your hard disk, each file on the disk is recorded
>>>in the MFT, the operating system uses the MFT to find your files and to
>>>record information about the files.
>>>
>>>Because MFT fragmentation can degrade performance the file system
>>>preemptively reserves a large contiguous block for the MFT when the
>>>drive is formatted. This space isn't lost, it will be used if needed. If
>>>the disk runs out of space for files the file system will relent and
>>>yield space for the files from the MFT zone. The opposite is also true,
>>>if the MFT zone fills up it will take space from the available (free)
>>>disk space for its needs, the problem there is that in both instances
>>>the MFT will become fragmented and the built in disk defragmenter will
>>>not be able to defragment it. Also note that small files of 1KB or less
>>>are stored in the MFT.
>>>
>>>John
>>
>>
>> Just curious here. I used diskeeper version 8. There is no designation
>> for MFT usage area in the graphical representaton of the XP windows
>> partition. There is an area called "reserved system", and yet another for
>> the swapfile itself.
>>
>> On one PC, the reserved system area is small, 17GB partition. On another
>> PC, the reserved system area is comparatively large, about ten times
>> bigger graphically, swapfile is about the same size, 26GB partition. The
>> latter sees little changes, very little internet, few MS updates, mostly
>> one game usage is all it sees most of the time. The former is used alot
>> on the internet, this one I'm using now, has all MS updates, Office usage
>> when on and offline. Both are NTFS version 3.1 of course. Why the
>> disparity?
>
> Yes, I have found out about that a little while ago and much like you I
> have found this to be inconsistent. One, if unlikely, possibility would
> be that the default NtfsMftZoneReservation area would have been changed in
> the registry and that one disk would have a larger than 12.5% MFT zone.
> But more than likely the explanation here
> http://www.diskeeperblog.com/archives/2006/11/the_mystery_of.html explains
> your findings.
>
> John

I'd bite on the explanation regarding diskeeper's shrinking graphical
representation of the reserved system area, but, its always been relatively
small. And, nowhere near the 12.5% thing on the PC with the smaller
reserved system space. I install diskeeper immediately after satisfied with
XP installation. Thanks for you input.
--
Dave
 >> Stay informed about: ""Reserved for MFT""? 

Dave

Both are NTFS version 3.1 of course.

Did you mean to say that? Isn't that pre XP?


~~~~


Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~

Lil' Dave wrote:
> "John John (MVP)" wrote in message
>
>> Jim wrote:
>>
>>> While defragging my C: drive, there is a pretty large sector
>>> saying Reserved For MFT. Can anyone explain just what
>>> that space is needed for?
>>
>> It's reserved space for the Master File Table. The MFT is one of
>> the most important files on your hard disk, each file on the disk is
>> recorded in the MFT, the operating system uses the MFT to find your
>> files and to record information about the files.
>>
>> Because MFT fragmentation can degrade performance the file system
>> preemptively reserves a large contiguous block for the MFT when the
>> drive is formatted. This space isn't lost, it will be used if
>> needed. If the disk runs out of space for files the file system will
>> relent and yield space for the files from the MFT zone. The opposite
>> is also true, if the MFT zone fills up it will take space from the
>> available (free) disk space for its needs, the problem there is that
>> in both instances the MFT will become fragmented and the built in
>> disk defragmenter
>> will not be able to defragment it. Also note that small files of 1KB
>> or less are stored in the MFT.
>>
>> John
>
> Just curious here. I used diskeeper version 8. There is no
> designation for MFT usage area in the graphical representaton of the
> XP windows partition. There is an area called "reserved system", and
> yet another for the swapfile itself.
>
> On one PC, the reserved system area is small, 17GB partition. On
> another PC, the reserved system area is comparatively large, about
> ten times bigger graphically, swapfile is about the same size, 26GB
> partition. The latter sees little changes, very little internet, few
> MS updates, mostly one game usage is all it sees most of the time. The
> former is used alot on the internet, this one I'm using now, has
> all MS updates, Office usage when on and offline. Both are NTFS
> version 3.1 of course. Why the disparity?
 >> Stay informed about: ""Reserved for MFT""? 

John

My feeling is that an MFT in two fragments is par for the course. I feel
sure I got an explanation from Greg Hayes some years ago why this is so
but I can now no longer find or remember the explanation he gave. On
this system I have three fragments on the C partition and two on the
other partitions.


~~~~


Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~



John John (MVP) wrote:
> Actually there are two things at work on Windows XP. The first one is
> that on XP the MFT is apparently just an NTFS-hint, it no longer
> reserves large contiguous blocks for the MFT and the defragmenter can
> defrag in and out of the MFT. That is the theory... but in practice
> it doesn't always work like that. This is still fairly new to me but
> my findings have been that there may still be a minimum of 12.5% of
> the drive reserved for the MFT zone on Windows XP installations and
> that when (if) there is no such large reserved zone (NTFS-hint) the
> defragmenter still does not fully defragment the MFT, I have seen it
> in two fragments in my test and I can run defrag in GUI or
> command-line mode until the cows come home and the MFT is still left
> in two fragments. Documentation on this is scant and I haven't done
> extensive testing so I don't know what exactly is going on with this.
> I think that the differences may be whether the drive is formatted by
> the XP setup program or whether it is formatted by an up and running
> XP installation. This is just a guess, I haven't had time to do more
> test on this. Greg from Raxco could probably shed more light on this
> but I haven't seen him in the groups for a little while...
>
> John
>
> Gerry wrote:
>
>> John
>>
>> I am not sure I can reconcile your last paragraph with this extract
>> from KB 227463
>>
>> In Windows 2000, it does not defragment NTFS metadata files, such as
>> the Master File Table (MFT), or the metadata that describes a
>> directory's contents. This limitation has been removed in Windows XP
>> and later. It cannot defragment encrypted files in Windows 2000.
>> This limitation has been removed in Windows XP and later.
>> Disk Defragmenter Limitations in Windows 2000, Windows XP, and
>> Windows Server 2003
>> http://support.microsoft.com/kb/227463
>>
>>
>> ~~~~
>>
>>
>> Gerry
>> ~~~~
>> FCA
>> Stourport, England
>> Enquire, plan and execute
>> ~~~~~~~~~~~~~~~~~~~
>>
>>
>> John John (MVP) wrote:
>>
>>> Jim wrote:
>>>
>>>
>>>> While defragging my C: drive, there is a pretty large sector
>>>> saying Reserved For MFT. Can anyone explain just what
>>>> that space is needed for?
>>>
>>> It's reserved space for the Master File Table. The MFT is one of
>>> the most important files on your hard disk, each file on the disk is
>>> recorded in the MFT, the operating system uses the MFT to find your
>>> files and to record information about the files.
>>>
>>> Because MFT fragmentation can degrade performance the file system
>>> preemptively reserves a large contiguous block for the MFT when the
>>> drive is formatted. This space isn't lost, it will be used if
>>> needed. If the disk runs out of space for files the file system
>>> will relent and yield space for the files from the MFT zone. The
>>> opposite is also true, if the MFT zone fills up it will take space
>>> from the available (free) disk space for its needs, the problem
>>> there is that in both instances the MFT will become fragmented and
>>> the built in disk defragmenter will not be able to defragment it.
>>> Also note that small files of 1KB or less are stored in the MFT.
>>>
>>> John
 >> Stay informed about: ""Reserved for MFT""? 

According to the (scant) information available from Microsoft, one would
think that the XP defragmenter should be able to defragment the MFT on
your C: drive and have it in no more than 2 segments, there are
inconsistencies with this NTFS-hint thing and MFT fragmentation.
Clearly the MFT on your C: drive is fragmented and the defragmenter
hasn't rearranged it and on some XP systems there is still a reserved
12.5% MFT zone instead of the NTFS-hint, I'm not sure what to make of
all of this, I will have to do more testing a research.

John

Gerry wrote:

> John
>
> My feeling is that an MFT in two fragments is par for the course. I feel
> sure I got an explanation from Greg Hayes some years ago why this is so
> but I can now no longer find or remember the explanation he gave. On
> this system I have three fragments on the C partition and two on the
> other partitions.
>
>
> ~~~~
>
>
> Gerry
> ~~~~
> FCA
> Stourport, England
> Enquire, plan and execute
> ~~~~~~~~~~~~~~~~~~~
>
>
>
> John John (MVP) wrote:
>
>>Actually there are two things at work on Windows XP. The first one is
>>that on XP the MFT is apparently just an NTFS-hint, it no longer
>>reserves large contiguous blocks for the MFT and the defragmenter can
>>defrag in and out of the MFT. That is the theory... but in practice
>>it doesn't always work like that. This is still fairly new to me but
>>my findings have been that there may still be a minimum of 12.5% of
>>the drive reserved for the MFT zone on Windows XP installations and
>>that when (if) there is no such large reserved zone (NTFS-hint) the
>>defragmenter still does not fully defragment the MFT, I have seen it
>>in two fragments in my test and I can run defrag in GUI or
>>command-line mode until the cows come home and the MFT is still left
>>in two fragments. Documentation on this is scant and I haven't done
>>extensive testing so I don't know what exactly is going on with this.
>>I think that the differences may be whether the drive is formatted by
>>the XP setup program or whether it is formatted by an up and running
>>XP installation. This is just a guess, I haven't had time to do more
>>test on this. Greg from Raxco could probably shed more light on this
>>but I haven't seen him in the groups for a little while...
>>
>>John
>>
>>Gerry wrote:
>>
>>
>>>John
>>>
>>>I am not sure I can reconcile your last paragraph with this extract
>>>from KB 227463
>>>
>>>In Windows 2000, it does not defragment NTFS metadata files, such as
>>>the Master File Table (MFT), or the metadata that describes a
>>>directory's contents. This limitation has been removed in Windows XP
>>>and later. It cannot defragment encrypted files in Windows 2000.
>>>This limitation has been removed in Windows XP and later.
>>>Disk Defragmenter Limitations in Windows 2000, Windows XP, and
>>>Windows Server 2003
>>>http://support.microsoft.com/kb/227463
>>>
>>>
>>>~~~~
>>>
>>>
>>>Gerry
>>>~~~~
>>>FCA
>>>Stourport, England
>>>Enquire, plan and execute
>>>~~~~~~~~~~~~~~~~~~~
>>>
>>>
>>>John John (MVP) wrote:
>>>
>>>
>>>>Jim wrote:
>>>>
>>>>
>>>>
>>>>>While defragging my C: drive, there is a pretty large sector
>>>>>saying Reserved For MFT. Can anyone explain just what
>>>>>that space is needed for?
>>>>
>>>>It's reserved space for the Master File Table. The MFT is one of
>>>>the most important files on your hard disk, each file on the disk is
>>>>recorded in the MFT, the operating system uses the MFT to find your
>>>>files and to record information about the files.
>>>>
>>>>Because MFT fragmentation can degrade performance the file system
>>>>preemptively reserves a large contiguous block for the MFT when the
>>>>drive is formatted. This space isn't lost, it will be used if
>>>>needed. If the disk runs out of space for files the file system
>>>>will relent and yield space for the files from the MFT zone. The
>>>>opposite is also true, if the MFT zone fills up it will take space
>>>>from the available (free) disk space for its needs, the problem
>>>>there is that in both instances the MFT will become fragmented and
>>>>the built in disk defragmenter will not be able to defragment it.
>>>>Also note that small files of 1KB or less are stored in the MFT.
>>>>
>>>>John
>
>
>
 >> Stay informed about: ""Reserved for MFT""? 

Hi,

The second fragment of the $MFT is the MFT mirror.
http://tinyurl.com/63hw8o

I'll copy-paste the relevant passage from the 'Analysis and
Defragmentation' section.

- That second bit of green in the middle of the disk is the MFT Mirror.
The first dozen or so blocks of the MFT (Master File Table) are
critical; if you lose them, you lose everything on the drive. Those
blocks are duplicated in the MFT Mirror, which is positioned in the
middle of the disk. This makes it very difficult to lose both copies.
You may have noticed that the MFT always has at least two fragments;
you can't get it to one fragment. That extra fragment usually
represents the MFT Mirror.-

Hope this helps
Best regards
-------------------
Representative
Diskeeper Corporation
---------------------

Gerry;3164363 Wrote:
> John
>
> My feeling is that an MFT in two fragments is par for the course. I
> feel
> sure I got an explanation from Greg Hayes some years ago why this is so
>
> but I can now no longer find or remember the explanation he gave. On
> this system I have three fragments on the C partition and two on the
> other partitions.
>
>
> ~~~~
>
>
> Gerry
> ~~~~
> FCA
> Stourport, England
> Enquire, plan and execute
> ~~~~~~~~~~~~~~~~~~~
>
>
>
> John John (MVP) wrote:-
> Actually there are two things at work on Windows XP. The first one
> is
> that on XP the MFT is apparently just an NTFS-hint, it no longer
> reserves large contiguous blocks for the MFT and the defragmenter can
> defrag in and out of the MFT. That is the theory... but in practice
> it doesn't always work like that. This is still fairly new to me but
> my findings have been that there may still be a minimum of 12.5% of
> the drive reserved for the MFT zone on Windows XP installations and
> that when (if) there is no such large reserved zone (NTFS-hint) the
> defragmenter still does not fully defragment the MFT, I have seen it
> in two fragments in my test and I can run defrag in GUI or
> command-line mode until the cows come home and the MFT is still left
> in two fragments. Documentation on this is scant and I haven't done
> extensive testing so I don't know what exactly is going on with this.
> I think that the differences may be whether the drive is formatted by
> the XP setup program or whether it is formatted by an up and running
> XP installation. This is just a guess, I haven't had time to do more
> test on this. Greg from Raxco could probably shed more light on this
> but I haven't seen him in the groups for a little while...
>
> John
>
> Gerry wrote:
> -
> John
>
> I am not sure I can reconcile your last paragraph with this extract
> from KB 227463
>
> In Windows 2000, it does not defragment NTFS metadata files, such as
> the Master File Table (MFT), or the metadata that describes a
> directory's contents. This limitation has been removed in Windows XP
> and later. It cannot defragment encrypted files in Windows 2000.
> This limitation has been removed in Windows XP and later.
> Disk Defragmenter Limitations in Windows 2000, Windows XP, and
> Windows Server 2003
> http://support.microsoft.com/kb/227463
>
>
> ~~~~
>
>
> Gerry
> ~~~~
> FCA
> Stourport, England
> Enquire, plan and execute
> ~~~~~~~~~~~~~~~~~~~
>
>
> John John (MVP) wrote:
> -
> Jim wrote:
>
>
> While defragging my C: drive, there is a pretty large sector
> saying Reserved For MFT. Can anyone explain just what
> that space is needed for?
>
> It's reserved space for the Master File Table. The MFT is one of
> the most important files on your hard disk, each file on the disk is
> recorded in the MFT, the operating system uses the MFT to find your
> files and to record information about the files.
>
> Because MFT fragmentation can degrade performance the file system
> preemptively reserves a large contiguous block for the MFT when the
> drive is formatted. This space isn't lost, it will be used if
> needed. If the disk runs out of space for files the file system
> will relent and yield space for the files from the MFT zone. The
> opposite is also true, if the MFT zone fills up it will take space
> from the available (free) disk space for its needs, the problem
> there is that in both instances the MFT will become fragmented and
> the built in disk defragmenter will not be able to defragment it.
> Also note that small files of 1KB or less are stored in the MFT.
>
> John ---




--
DiskeeperRep
 >> Stay informed about: ""Reserved for MFT""? 

How about the built-in Windows defragmenter? Are you saying that it
treats the $MFT and the $MFTMirr as one file and that that is why the
built-in defragmenter always shows it (the MFT) as being in two segments?

John

DiskeeperRep wrote:

> Hi,
>
> The second fragment of the $MFT is the MFT mirror.
> http://tinyurl.com/63hw8o
>
> I'll copy-paste the relevant passage from the 'Analysis and
> Defragmentation' section.
>
> - That second bit of green in the middle of the disk is the MFT Mirror.
> The first dozen or so blocks of the MFT (Master File Table) are
> critical; if you lose them, you lose everything on the drive. Those
> blocks are duplicated in the MFT Mirror, which is positioned in the
> middle of the disk. This makes it very difficult to lose both copies.
> You may have noticed that the MFT always has at least two fragments;
> you can't get it to one fragment. That extra fragment usually
> represents the MFT Mirror.-
>
> Hope this helps
> Best regards
> -------------------
> Representative
> Diskeeper Corporation
> ---------------------
>
> Gerry;3164363 Wrote:
>
>>John
>>
>>My feeling is that an MFT in two fragments is par for the course. I
>>feel
>>sure I got an explanation from Greg Hayes some years ago why this is so
>>
>>but I can now no longer find or remember the explanation he gave. On
>>this system I have three fragments on the C partition and two on the
>>other partitions.
>>
>>
>>~~~~
>>
>>
>>Gerry
>>~~~~
>>FCA
>>Stourport, England
>>Enquire, plan and execute
>>~~~~~~~~~~~~~~~~~~~
>>
>>
>>
>>John John (MVP) wrote:-
>>Actually there are two things at work on Windows XP. The first one
>>is
>>that on XP the MFT is apparently just an NTFS-hint, it no longer
>>reserves large contiguous blocks for the MFT and the defragmenter can
>>defrag in and out of the MFT. That is the theory... but in practice
>>it doesn't always work like that. This is still fairly new to me but
>>my findings have been that there may still be a minimum of 12.5% of
>>the drive reserved for the MFT zone on Windows XP installations and
>>that when (if) there is no such large reserved zone (NTFS-hint) the
>>defragmenter still does not fully defragment the MFT, I have seen it
>>in two fragments in my test and I can run defrag in GUI or
>>command-line mode until the cows come home and the MFT is still left
>>in two fragments. Documentation on this is scant and I haven't done
>>extensive testing so I don't know what exactly is going on with this.
>>I think that the differences may be whether the drive is formatted by
>>the XP setup program or whether it is formatted by an up and running
>>XP installation. This is just a guess, I haven't had time to do more
>>test on this. Greg from Raxco could probably shed more light on this
>>but I haven't seen him in the groups for a little while...
>>
>>John
>>
>>Gerry wrote:
>>-
>>John
>>
>>I am not sure I can reconcile your last paragraph with this extract
>>from KB 227463
>>
>>In Windows 2000, it does not defragment NTFS metadata files, such as
>>the Master File Table (MFT), or the metadata that describes a
>>directory's contents. This limitation has been removed in Windows XP
>>and later. It cannot defragment encrypted files in Windows 2000.
>>This limitation has been removed in Windows XP and later.
>>Disk Defragmenter Limitations in Windows 2000, Windows XP, and
>>Windows Server 2003
>>http://support.microsoft.com/kb/227463
>>
>>
>>~~~~
>>
>>
>>Gerry
>>~~~~
>>FCA
>>Stourport, England
>>Enquire, plan and execute
>>~~~~~~~~~~~~~~~~~~~
>>
>>
>>John John (MVP) wrote:
>>-
>>Jim wrote:
>>
>>
>>While defragging my C: drive, there is a pretty large sector
>>saying Reserved For MFT. Can anyone explain just what
>>that space is needed for?
>>
>>It's reserved space for the Master File Table. The MFT is one of
>>the most important files on your hard disk, each file on the disk is
>>recorded in the MFT, the operating system uses the MFT to find your
>>files and to record information about the files.
>>
>>Because MFT fragmentation can degrade performance the file system
>>preemptively reserves a large contiguous block for the MFT when the
>>drive is formatted. This space isn't lost, it will be used if
>>needed. If the disk runs out of space for files the file system
>>will relent and yield space for the files from the MFT zone. The
>>opposite is also true, if the MFT zone fills up it will take space
>>from the available (free) disk space for its needs, the problem
>>there is that in both instances the MFT will become fragmented and
>>the built in disk defragmenter will not be able to defragment it.
>>Also note that small files of 1KB or less are stored in the MFT.
>>
>>John ---
>
>
>
>
>
 >> Stay informed about: ""Reserved for MFT""? 

Thanks for your contribution. I had read elsewhere about references to
there being an MFT mirror. However, I do not think your comments
regarding unmoveable files reveals the whole story. The pagefile and the
MFT combine in the graphical interface to form a single solid green
block slightly off left of the centre on my system say 35% to 45% from
the start. It is of course not possible to see which part represents the
pagefile and which the MFT. It is relevant to point out that I have set
a minimum = maximum pagefile to avoid the problem of the pagefile for
ever making other files fragment more quickly than they need. The
pagefile would appear to be contiguous given that it is a single
fragment.

My C drive does have three MFT fragments ( two on all other
partitions ). This does not show up in the graphical display. Is this a
result of the way I have set up my pagefile or something else?



~~~~


Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~



DiskeeperRep wrote:
> Hi,
>
> The second fragment of the $MFT is the MFT mirror.
> http://tinyurl.com/63hw8o
>
> I'll copy-paste the relevant passage from the 'Analysis and
> Defragmentation' section.
>
> - That second bit of green in the middle of the disk is the MFT
> Mirror. The first dozen or so blocks of the MFT (Master File Table)
> are critical; if you lose them, you lose everything on the drive.
> Those blocks are duplicated in the MFT Mirror, which is positioned in
> the middle of the disk. This makes it very difficult to lose both
> copies. You may have noticed that the MFT always has at least two
> fragments; you can't get it to one fragment. That extra fragment
> usually represents the MFT Mirror.-
>
> Hope this helps
> Best regards
> -------------------
> Representative
> Diskeeper Corporation
> ---------------------
>
> Gerry;3164363 Wrote:
>> John
>>
>> My feeling is that an MFT in two fragments is par for the course. I
>> feel
>> sure I got an explanation from Greg Hayes some years ago why this is
>> so
>>
>> but I can now no longer find or remember the explanation he gave. On
>> this system I have three fragments on the C partition and two on the
>> other partitions.
>>
>>
>> ~~~~
>>
>>
>> Gerry
>> ~~~~
>> FCA
>> Stourport, England
>> Enquire, plan and execute
>> ~~~~~~~~~~~~~~~~~~~
>>
>>
>>
>> John John (MVP) wrote:-
>> Actually there are two things at work on Windows XP. The first one
>> is
>> that on XP the MFT is apparently just an NTFS-hint, it no longer
>> reserves large contiguous blocks for the MFT and the defragmenter can
>> defrag in and out of the MFT. That is the theory... but in practice
>> it doesn't always work like that. This is still fairly new to me but
>> my findings have been that there may still be a minimum of 12.5% of
>> the drive reserved for the MFT zone on Windows XP installations and
>> that when (if) there is no such large reserved zone (NTFS-hint) the
>> defragmenter still does not fully defragment the MFT, I have seen it
>> in two fragments in my test and I can run defrag in GUI or
>> command-line mode until the cows come home and the MFT is still left
>> in two fragments. Documentation on this is scant and I haven't done
>> extensive testing so I don't know what exactly is going on with this.
>> I think that the differences may be whether the drive is formatted by
>> the XP setup program or whether it is formatted by an up and running
>> XP installation. This is just a guess, I haven't had time to do more
>> test on this. Greg from Raxco could probably shed more light on this
>> but I haven't seen him in the groups for a little while...
>>
>> John
>>
>> Gerry wrote:
>> -
>> John
>>
>> I am not sure I can reconcile your last paragraph with this extract
>> from KB 227463
>>
>> In Windows 2000, it does not defragment NTFS metadata files, such as
>> the Master File Table (MFT), or the metadata that describes a
>> directory's contents. This limitation has been removed in Windows XP
>> and later. It cannot defragment encrypted files in Windows 2000.
>> This limitation has been removed in Windows XP and later.
>> Disk Defragmenter Limitations in Windows 2000, Windows XP, and
>> Windows Server 2003
>> http://support.microsoft.com/kb/227463
>>
>>
>> ~~~~
>>
>>
>> Gerry
>> ~~~~
>> FCA
>> Stourport, England
>> Enquire, plan and execute
>> ~~~~~~~~~~~~~~~~~~~
>>
>>
>> John John (MVP) wrote:
>> -
>> Jim wrote:
>>
>>
>> While defragging my C: drive, there is a pretty large sector
>> saying Reserved For MFT. Can anyone explain just what
>> that space is needed for?
>>
>> It's reserved space for the Master File Table. The MFT is one of
>> the most important files on your hard disk, each file on the disk is
>> recorded in the MFT, the operating system uses the MFT to find your
>> files and to record information about the files.
>>
>> Because MFT fragmentation can degrade performance the file system
>> preemptively reserves a large contiguous block for the MFT when the
>> drive is formatted. This space isn't lost, it will be used if
>> needed. If the disk runs out of space for files the file system
>> will relent and yield space for the files from the MFT zone. The
>> opposite is also true, if the MFT zone fills up it will take space
>> from the available (free) disk space for its needs, the problem
>> there is that in both instances the MFT will become fragmented and
>> the built in disk defragmenter will not be able to defragment it.
>> Also note that small files of 1KB or less are stored in the MFT.
>>
>> John ---
 >> Stay informed about: ""Reserved for MFT""?