What is "Reserved System Space" and what can I do with it?

MAP

He already has <G>.


--
Regards.

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


MAP wrote:
> Cyril N. Alberga wrote:
>> Perhaps I see what is happening then. All the disks were set to 12%,
>> which is the highest that "My Computer" seems to allow, while 1% is
>> the lowest. I had tried the 1% values based on someone up-thread
>> saying that 750 Mbytes (I think) should be sufficient, and 1% gave
>> over 2 Gbytes. My confusion was based on the fact that all the other
>> disks had much smaller areas marked as "reserved", even though they
>> are shown as 12% in the "property" box. I suppose the space has been
>> used for data files, as most of the disks are fairly full.
>> Thanks to everyone who has helped clear up my puzzlement.
>>
>> Cyril
>>
>> John John wrote:
>>> You can't push the MFT Zone reservation to 1%. The
>>> NtfsMftZoneReservation is set in the registry, possible values for
>>> the entry and the corresponding reserved space are:
>>>
>>> 1 = 12.5%
>>> 2 = 25%
>>> 3 = 37.5%
>>> 4 = 50%
>>>
>>> You already have this set to the lowest possible value.
>>>
>>> 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 when
>>> 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. When either of
>>> these happen 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
>>>
>>> Cyril N. Alberga wrote:
>>>
>>>> Thank you -- I think... I followed the instructions, there were
>>>> 12% of the disk reserved, and I pushed it down to 1% (a bit over 1
>>>> gig). But diskeeper still thinks there is a hugh chunk. Do I have
>>>> to shutdown and restart before I see the effects?
>>>>
>>>> Cyril
>>>>
>>>> JS wrote:
>>>>
>>>>> See: http://answers.google.com/answers/threadview?id=780063
>>>>>
>>>>> JS
>>>>>
>>>>> "Cyril N. Alberga" <calberga@bellatlantic.net> wrote in message
>>>>> news:eDiboQdiIHA.4536@TK2MSFTNGP06.phx.gbl...
>>>>>
>>>>>> I'm running XP Pro, SP2.
>>>>>>
>>>>>> I recently did two things.
>>>>>>
>>>>>> First, I took a 250 GByte FAT external harddrive, backed it
>>>>>> contents up to another drive and reformatted it as NTFS, then
>>>>>> restored the contents.
>>>>>>
>>>>>> Second, I installed an incremental defrag program, Diskeeper, on
>>>>>> my system. When I looked at the newly reformatted drive Diskeeper
>>>>>> reports that over 10% is "Reserved System Space". This is an
>>>>>> order of magnitude more than on any of my other 250 or 300 Gbyte
>>>>>> drives, or even my one 500 Gbyte drive.
>>>>>>
>>>>>> Could this be an error in the defrag program? (The company says
>>>>>> no.) If such a large chunk of the drive is reserved does that
>>>>>> mean that it will never be used for my data? Is there any way to
>>>>>> shrink this allocation?
>>>>>>
>>>>>> I hope this is the right place to ask this.
>>>>>>
>>>>>> Cyril N. Alberga
>
> Do not confuse the MFT with system restore.

why the hell does it have to be at least 12%? every entry is roughly 1kb, so even with 1m files on a disk you require only 1gb of MFT space.. and having 60gb 'reserved' space on a 500GB drive is absolutely ridiculous, and wreaks havoc on defragmentation efficiency of near-full drives.

Are you referring to the Recycle Bin? Be more specific.

<foppe de Haan> wrote in message news:2008516111110aarskever@zonnet.nl...
> why the hell does it have to be at least 12%? every entry is roughly 1kb,
> so even with 1m files on a disk you require only 1gb of MFT space.. and
> having 60gb 'reserved' space on a 500GB drive is absolutely ridiculous,
> and wreaks havoc on defragmentation efficiency of near-full drives.

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

foppe de Haan wrote:

> why the hell does it have to be at least 12%? every entry is roughly
1kb, so even with 1m files on a disk you require only 1gb of MFT space..
and having 60gb 'reserved' space on a 500GB drive is absolutely
ridiculous, and wreaks havoc on defragmentation efficiency of near-full
drives.

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, .

To see exactly how large the MFT is, you can use the built-in
defragmenter to analyze the volume. The resulting report provides
detailed information about the size and number of fragments in the MFT.

For example:
Master File Table (MFT) fragmentation
Total MFT size = 26,203 KB
MFT record count = 21,444
Percent MFT in use = 81 %
Total MFT fragments = 4

However, for more complete information about how much space (overhead)
the whole NTFS is using, run the chkdsk.exe command, and then view the
output for the following line:
In use by system.

Currently, only third-party defragmenters consolidate unused MFT FRS
records and reclaim unused MFT allocated spaceNTFS MFT Expansion
http://support.microsoft.com/kb/315688
http://support.microsoft.com/kb/814594

Reserved space. Further reading:
http://msdn.microsoft.com/en-us/libr...30(VS.85).aspx
http://support.microsoft.com/kb/174619

--



Hope this helps.

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

foppe de Haan wrote:
> why the hell does it have to be at least 12%? every entry is roughly
> 1kb, so even with 1m files on a disk you require only 1gb of MFT
> space.. and having 60gb 'reserved' space on a 500GB drive is
> absolutely ridiculous, and wreaks havoc on defragmentation efficiency
> of near-full drives.

Gerry wrote:
> 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, .
>
> To see exactly how large the MFT is, you can use the built-in
> defragmenter to analyze the volume. The resulting report provides
> detailed information about the size and number of fragments in the MFT.
>
> For example:
> Master File Table (MFT) fragmentation
> Total MFT size = 26,203 KB
> MFT record count = 21,444
> Percent MFT in use = 81 %
> Total MFT fragments = 4
>
> However, for more complete information about how much space (overhead)
> the whole NTFS is using, run the chkdsk.exe command, and then view the
> output for the following line:
> In use by system.
>
> Currently, only third-party defragmenters consolidate unused MFT FRS
> records and reclaim unused MFT allocated spaceNTFS MFT Expansion
> http://support.microsoft.com/kb/315688
> http://support.microsoft.com/kb/814594
>
> Reserved space. Further reading:
> http://msdn.microsoft.com/en-us/libr...30(VS.85).aspx
> http://support.microsoft.com/kb/174619
>

My MTF files is 77MB. Just curious as to how large that is compared to
others' MTF size.

Richard

foppe de Haan is complaining about the amount of reserved space ( 12.5%
of the six=ze of the partition / drive) not the amount actually being
used by the MFT.

The MFT on my Windows partition is 79 mb. However, I have a number of
partitions, each with it's own MFT. There is a direct correlation
between the number of files and folders and the size of the MFT.

--



Hope this helps.

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

richard wrote:
> Gerry wrote:
>> 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, .
>>
>> To see exactly how large the MFT is, you can use the built-in
>> defragmenter to analyze the volume. The resulting report provides
>> detailed information about the size and number of fragments in the
>> MFT. For example:
>> Master File Table (MFT) fragmentation
>> Total MFT size = 26,203 KB
>> MFT record count = 21,444
>> Percent MFT in use = 81 %
>> Total MFT fragments = 4
>>
>> However, for more complete information about how much space
>> (overhead) the whole NTFS is using, run the chkdsk.exe command, and
>> then view the output for the following line:
>> In use by system.
>>
>> Currently, only third-party defragmenters consolidate unused MFT FRS
>> records and reclaim unused MFT allocated spaceNTFS MFT Expansion
>> http://support.microsoft.com/kb/315688
>> http://support.microsoft.com/kb/814594
>>
>> Reserved space. Further reading:
>> http://msdn.microsoft.com/en-us/libr...30(VS.85).aspx
>> http://support.microsoft.com/kb/174619
>>
>
> My MTF files is 77MB. Just curious as to how large that is compared to
> others' MTF size.