Pagefile on mounted drive has incorrect size

[Dark Daskin]

I'm trying to move my page file to dedicated partition. I have system
partition mounted on C: and swap partition mounted on C:\Swap. C: has 200 MB
free, and C:\Swap has 2 GB free. I set value of
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory
Management\PagingFiles to C:\Swap\pagefile.sys 2048 2048.
When I rebooted my computer, I have seen that size of C:\Swap\pagefile.sys
is about 200 MB despite of registry settings. I think it's because system
doesn't check if path to pagefile is on another partition (it looks like a
bug). I dont want to give a drive letter to swap partition. Is there another
way to place pagefile on the partition without drive letter?

 

[Gerry]

Each partition has it's own letter. The partition containing Windows
(with only a few exceptions) is invariably C. If your page file is in
it's own dedicated partition that partition will be some other letter
other than C!

What tool or utility did you use the create the partition?

Whilst there are conflicting views on the merits of creating dedicated
pagefile partitions all agree that such a partition should be on a
second drive, preferably the first partition on that drive. They should
not be on the same drive as the system partition.
http://aumha.org/win5/a/xpvm.htm

Here is some general information concerning the differences between
drives, partitions etc, which may help:
http://en.wikipedia.org/wiki/Partition_(computing)

--



Hope this helps.

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

 

[Leonard Grey]

The idea is to move the page file to a separate partition on a second
hard disk, not a separate partition on the same hard disk. The latter
course of action will reduce performance.

"How to configure paging files for optimization and recovery in Windows XP"
http://support.microsoft.com/kb/314482

Nonetheless, you are unlikely to notice a difference in your computer's
performance unless the disk to which you transfer the page file is
substantially faster and substantially less accessed than the disk on
which your system partition is located. And to the extent your day to
day computing does not involve considerable paging, you won't notice any
difference at all.

 

[Gerry]

Leonard

Separating the pagefile from other files does slow the impact of
fragmentation on the other files. You also no longer need to maintain
that part of the disk occupied by the pagefile. Equally if you can place
constantly changing files away from archived files you reduce the time
needed to run Disk Defragmenter etc because you are working on a smaller
part of the drive. These points may not have a dramatic impact but they
help achieve better performance.

I wrote this note as a reaction to your observation "Nonetheless, you
are unlikely to notice a difference in your computer's performance" and
totally agree with the earlier part of your post.

--
Regards.

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

 

[Leonard Grey]

Hi Gerry:

Always good to read your posts.

Outside the lab I seriously doubt anyone would notice the delta in
performance attributable to reduced fragmentation resulting from the
relocation of the page file. Also: The question of whether or not a home
user realizes any noticeable benefit by supposedly optimal file
placement is controversial (unless you're a marketing manager for a
third-party defragger - and even they don't agree of whose method of
'optimal file placement' is best.) Busy servers are a different
story...I agree that they almost certainly benefit by improved disk
organization.

With regard to the length of time needed to defragment a volume without
a page file, I believe that any benefit so gained would vanish after the
first post-page file pass of the defragger.

Then again, a lot depends on how you use your computer. If someone
reviews software for a living or is heavily into Photoshop or video
editing they could probably throw my opinions in the trash, and rightly so.

 

[Jim]

Hi Gerry:

Always good to read your posts.

Outside the lab I seriously doubt anyone would notice the delta in
performance attributable to reduced fragmentation resulting from the
relocation of the page file. Also: The question of whether or not a home
user realizes any noticeable benefit by supposedly optimal file placement
is controversial (unless you're a marketing manager for a third-party
defragger - and even they don't agree of whose method of 'optimal file
placement' is best.) Busy servers are a different story...I agree that
they almost certainly benefit by improved disk organization.

With regard to the length of time needed to defragment a volume without a
page file, I believe that any benefit so gained would vanish after the
first post-page file pass of the defragger.

Then again, a lot depends on how you use your computer. If someone reviews
software for a living or is heavily into Photoshop or video editing they
could probably throw my opinions in the trash, and rightly so.

Would not you two agree that, as the pagefile is hardly ever read as a
sequential file, fragmentation of it is not likely to cause performance
degradation.
Moreover, even if it is, to the outside world, all one piece, it could still
be internally fragemented.
Jim

 

[Leonard Grey]

You raise good points, Jim. However, I don't feel I'm sufficiently
versed to provide complete answers.

 

[Gerry]

Jim

The Disk Defragmenter provided with Windows XP does not defragmenter the
pagefile. Having said that I am not aware of any knowledgeable poster in
these newsgroups who recommends defragmenting a pagefile. It's a waste
of time.

You should not, however, confuse the ramnifications of a contiguous area
of disk space solely occupied by the pagefile with a non-contiguous
pagefile scattered over a complete system partition. The non-contiguous
pagefile fragments the available free disk space causing more rapid and
greater fragmentation of new files being written to disk.

--



Hope this helps.

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

 

[Ken Blake, MVP]

I'm trying to move my page file to dedicated partition.

Not a good idea. Doing so will *hurt* your performance, not help it.

The slowest aspect of using a hard drive is the time it takes for the
heads to move from one place to another. Moving the page file to a
second partition on your drive puts it far from the other
frequently-used data on the drive, increases the time for head
movement to and from it, and slows you down. Putting it on a second
*physical* drive improves performance (because that *decreases* head
movement) but not to a second partition on your only drive.

But wherever you put it, make sure you keep some on C:.

For more info, read MVP Alex Nichol's article at
http://www.aumha.org/win5/a/xpvm.htm

Also note that many people these days have enough RAM so that the page
file is hardly used at all. If you fall into that category, moving it
anywhere won't help.

 

[Jim]

I'm trying to move my page file to dedicated partition. I have system
partition mounted on C: and swap partition mounted on C:\Swap. C: has 200
MB
free, and C:\Swap has 2 GB free. I set value of
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory
Management\PagingFiles to C:\Swap\pagefile.sys 2048 2048.
When I rebooted my computer, I have seen that size of C:\Swap\pagefile.sys
is about 200 MB despite of registry settings. I think it's because system
doesn't check if path to pagefile is on another partition (it looks like a
bug). I dont want to give a drive letter to swap partition. Is there
another
way to place pagefile on the partition without drive letter?

Isn't it true that regardless of what you put in the registry, the system
will only expand the pagefile when it needs to do so? Not only that, XP
will never shrink the pagefile.
Jim

 

[Gerry]

Jim

Only correct if you opt for Let Windows ( the System) manage the page
file and there is free space on the hard disk. Setting a maximum
prevents expansion beyond the size set.


--



Hope this helps.

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

 

[Jim]

Jim

Only correct if you opt for Let Windows ( the System) manage the page file
and there is free space on the hard disk. Setting a maximum prevents
expansion beyond the size set.


--



Hope this helps.

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

Thanks. As I use "system managed size" in all cases, I would not know how
XP handles other cases.
Jim