"Fixed" size pagefile is growing all by itself

[Tiny Tim]

I've just rebuilt my Win XP Pro laptop this week and applied all MS updates.
I have 512MB RAM and like to set a custom pagefile size of 512MB-512MB in
contiguous disk space - i.e. fully defragged and unable to get fragged.
However, Windows seems to have taken it into its head to make my pagefile
768MB. If I go into the advanced performance settings I still see my 512-512
custom settings on the C: drive but Windows Explorer tells a different story
and the defrag disk analysis picture shows a huge pagefile fragged all over
the place.

I do not recall seeing this behaviour in the past. I am not running anywhere
near enough programs to even exceed the 512MB RAM and indeed, as I write
this I currently have the pagefile disabled altogether with no ill-effects.
I've tried the MS Knowledgebase and can see nothing about this little quirk.
Does anyone know why my pagefile has a mind of its own?

On a separate note I saw in the Knowledgebase that MS recommends setting up
the pagefile on a separate PARTITION from the system partition. I can see
the sense in a separate DRIVE but fail to see the merit in having the drive
heads skipping back and forth from system files to a separate partition. Can
anyone shed any light on why keeping the pagefile far apart from the system
files makes for a speedier system? Remember, my intention is to have a fixed
size 512MB pagefile that is not fragged and will not fragment if the size
stays fixed, and is physically close to the system files. It's just a pity
that Windows has other ideas.

Thanks for any help.
Tim.

 

[Guest]

I wish you were more specific. I don't see how you expect the pagefile to be unfragmented unless it's on its own drive or partition alone by itself. Still it would be subject to internal fragmentation. As to the Explorer reports of larger size, have you rebooted to implement changes?

 

[Tiny Tim]

I wish you were more specific. I don't see how you expect the
pagefile to be unfragmented unless it's on its own drive or partition
alone by itself. Still it would be subject to internal
fragmentation. As to the Explorer reports of larger size, have you
rebooted to implement changes?

It's very easy. You build the machine from scratch and Windows allocates a
pagefile of 1.5*memory - 768MB in my case. You delete the pagefile and
reboot. You defrag the partition, giving loads of clean clear space and then
you allocate a pagefile of custom size 512-512 MB. It gets set up as one
contiguous file in the clean space. A check with Defrag and Windows Explorer
confirms that the allocation size is correct and the pagefile is contiguous.
A few hours/days (I didn't check timings) I have magically got a bloated
pagefile that has become fragmented due to the increased size. Yet even in
the pagefile options dialogue I can see that my settings of 512-512 have
been remembered so why is it actually 768MB?

It will be subject to fragmentation if you allow its size to change or if
you allocate it when there is insufficient contiguous free space. I have
taken deliberate and specific steps to avoid the prospect of it becoming
fragmented. Windows seems to have other ideas.

At the moment I have no pagefile. Open apps include Outlook 2003, Outlook
Express, 3* Internet Explorer windows, Word 2003, Excel 2003 and other bits
and pieces running including AVG 7 antivirus and a TV Guide/Scheduler.
According to Task Manager my Commit Charge is currently 316MB and I have
peaked today at 339MB. So I'm still nowhere near needing a pagefile yet and
I certainly don't need one of 768MB.

Like I said (or implied, at least), this approach has worked for me in the
past following numerous rebuilds. It is only this month that Windows is
ignoring my clear instructions to set a pagefile of fixed size of 512MB. I
wonder if there has been an MS update that has caused this annoying
behaviour. After all, since an update in December we now have to put up with
Internet Explorer scrolling by two pages instead of one when clicking at one
end of the scroll bar or the other.

 

[Alex Nichol]

I've just rebuilt my Win XP Pro laptop this week and applied all MS updates.
I have 512MB RAM and like to set a custom pagefile size of 512MB-512MB in
contiguous disk space - i.e. fully defragged and unable to get fragged.
However, Windows seems to have taken it into its head to make my pagefile
768MB. If I go into the advanced performance settings I still see my 512-512
custom settings on the C: drive but Windows Explorer tells a different story
and the defrag disk analysis picture shows a huge pagefile fragged all over
the place.

Despite all that gets said, it is *not* a good idea to set the page file
Initial and maximum sizes the same. You need enough in Initial to cover
the normal need, (which I would expect to be quite a lot less than that
- but it depends on your workload) but have a substantially higher
maximum. What is probably happening is that programs are asking for
allocations of memory much bigger - that could have been assigned to the
potential space implied by a big maximum. Read up at
www.aumha.org/win5/a/xpvm.htm

 

[Tiny Tim]

Despite all that gets said, it is *not* a good idea to set the page
file Initial and maximum sizes the same. You need enough in Initial
to cover the normal need, (which I would expect to be quite a lot
less than that - but it depends on your workload) but have a
substantially higher maximum. What is probably happening is that
programs are asking for allocations of memory much bigger - that
could have been assigned to the potential space implied by a big
maximum. Read up at www.aumha.org/win5/a/xpvm.htm

OK, thanks for that. I have read the article and understand what it is
saying BUT.....

I am still running with no pagefile without any problems. I open pretty much
the same type and number of apps every day and my demands don't vary in
normal use. I have still got 2.05GB free space on my C: partition, 3.2GB
free on my D: partition and 3.0GB free (empty) on my E: partition so I know
Windows hasn't sneaked a pagefile onto the disk without my knowledge. Task
Manager is showing Commit Charge = 291308K, Peak = 303392K Limit = 494180K.

In other words, Windows is working just fine and well within the limits
imposed by 512MB RAM and NO pagefile. I therefore still do not understand
why, when I set a pagefile at a fixed size of 512-512MB, Windows feels it
has the right to allocate more space. There is no point in having the custom
settings if Windows is going to completely ignore them. That has nothing to
do with the rights and wrongs of my approach. I want to know why Windows
feels it knows best despite that fact that there is no need for any pagefile
with the number and type of apps I am running. I just want to understand
what is going on - I don't like mysteries. I've been running things "my way"
since XP came out and it is only this month that I have noticed Windows
playing silly buggers with my pagefile. Hopefully somebody has an answer to
why Windows has suddenly got a mind of its own.

 

[Alex Nichol]

In other words, Windows is working just fine and well within the limits
imposed by 512MB RAM and NO pagefile. I therefore still do not understand
why, when I set a pagefile at a fixed size of 512-512MB, Windows feels it
has the right to allocate more space.

It is trying to find space for those other allocations of memory that
programs have asked for and not used. It does not need real file, but
it does need the potential. So it has made a file - regardless. You
are *not* operating with no page file, but with the one it has made -
which is unnecessarily big. Give it a start point of 100 and a max say
800 or so , and you will never see the 100MB get any bigger - and there
will not be any actual traffic on it (20 or 30 MB of files may get
parked there on a 'just in case basis)

 

[Tiny Tim]

It is trying to find space for those other allocations of memory that
programs have asked for and not used. It does not need real file, but
it does need the potential. So it has made a file - regardless. You
are *not* operating with no page file, but with the one it has made -
which is unnecessarily big. Give it a start point of 100 and a max
say 800 or so , and you will never see the 100MB get any bigger - and
there will not be any actual traffic on it (20 or 30 MB of files may
get parked there on a 'just in case basis)

I'm afraid I remain confused. Having set NO PAGEFILE, there is no hint of a
pagefile on my system, hidden or otherwise. My disk free space confirms
there is no pagefile. A thorough search with Windows Explorer and TreeSize
Professional does not uncover one either. There really is no pagefile on my
system, judging likely candidates by name or size.

If, as you say, by allocating a pagefile of 100-800MB I will never see the
file grow beyond 100MB, why when I set the pagefile to 512-512 does it grow
to 768MB? This still does not add up.

Note that on rare occasions in the past I have seen a message from Windows
saying it was running out of memory and would allocate more, but in these
recent incidents, following a clean build, I am not getting such messages,
only the mysterious growth of the pagefile.

Perhaps I'll make a 128MB pagefile on each partition and see what Windows
does with that.

Cheers,
Tim.

 

[Yannis]

Hi there...

I have exactly the same problem. I set the pagefile to
200-200MB in size and windows just changes its size in
the next reboot back to 768MB, ingoring my previous
options. In the past that did not happen. This thing
started as soon as i installed Norton SystemsWorks 2004.
I tried everything so far, plus i updated all the
components of Norton but still nothing, windows just
refuses to keep my pagefile size settings. I made a
search through the newgroups and knowledgebase, and
although quite a few people have this problem, noone has
provided a working solution. And yes of course i hit
the "Set" button before rebooting my machine, and yes i
know that the pagefile has to be 1.5 times the amount of
system RAM. However, i WANT it to be *200-200MB* so has
anyone a solution to my problem? At the moment i am
operating without a pagefile.

Thanks in advance for your time.

Yannis

 

[Plato]

I have exactly the same problem. I set the pagefile to
200-200MB in size and windows just changes its size in

_Way_ too LOW for XP.........

the next reboot back to 768MB, ingoring my previous

IT does this to save your data because you dont know how to manually set
a swap file.

options. In the past that did not happen. This thing
started as soon as i installed Norton SystemsWorks 2004.

Because Nortons requires HUGE amounts of resources including tons of
swap file volume.

I tried everything so far, plus i updated all the

Try letting windows manage your pagefile for best results.

 

[Yannis]

Thanks for taking the time to reply. Let me answer in
respect to each part of your reply.

-----Original Message-----


_Way_ too LOW for XP.........

I don't think so, at least according to this article:
http://www.techspot.com/tweaks/memory-winxp/
Read page 4 - monitoring and calculating pagefile size

Apart from that 768MB is simply too much to commit on
Windows for virtual memory if you ask me!

IT does this to save your data because you dont know how

to manually set

If it does that then why on earth microsoft put the
custom initial and maximum allowed size in the first
place? At the end of the day Windows seems to have a mind
of its own...

a swap file.
2004.

Because Nortons requires HUGE amounts of resources including tons of
swap file volume.

Anything else to propose? How i can restrict windows from
reseting the pagefile size? does anyone know?

Thanks once again
Yannis

 

[Alex Nichol]

Thanks for taking the time to reply. Let me answer in
respect to each part of your reply.


I don't think so, at least according to this article:
http://www.techspot.com/tweaks/memory-winxp/
Read page 4 - monitoring and calculating pagefile size

Go and read my page - www.aumha.org/win5/a/xpvm.htm as well.
It is *not* a good idea to limit the Maximum size of the file, for
reasons explained there. And having the possibility of growth will do
not harm if the extra space over the initial size is not needed - you
should try to set Initial to cover the regular needs you have for actual
file.

 

[cquirke (MVP Win9x)]

Yannis wrote:

How much RAM do you have? The more RAM, the more swap you need in the
event of a crash that causes the system to dump into the swap. That
seems to be XP's logic, anyway; it assigns larger swap if more RAM
(e.g. something like 350M for 256M RAM, 760M for 512M RAM).

OTOH, for a given workload, the less RAM you have, the more swap you'd
expect to need. With that in mind - and bearing also in mind that I
use 1 user account only - I set min = max = 512M for any of 128M, 256M
or 512M RAM (I set the dump option to "minidump")

Go and read my page - www.aumha.org/win5/a/xpvm.htm as well.
It is *not* a good idea to limit the Maximum size of the file

Normally I'd agree - and I don't set a max on Win9x. But NT (XP)
seems to use a more dated strategy, as the defaults set both minimum
and maximum sizes (with a max that looks too small for 128M or 256M)

Given this swap is taken out of prime fast-volume real-estate, where
I'd like to keep entire file load down to < 4G, I don't like > 512M

------------ ----- --- -- - - - -

Drugs are usually safe. Inject? (Y/n)

 

[Alex Nichol]

How much RAM do you have? The more RAM, the more swap you need in the
event of a crash that causes the system to dump into the swap. That
seems to be XP's logic, anyway; it assigns larger swap if more RAM
(e.g. something like 350M for 256M RAM, 760M for 512M RAM).

If you do a mini-dump you need about 64 MB possible on the boot (system
to MSoft) drive. The system will get moody if it cannot achieve
something approaching this. In the case of kernel or full dumps it
appears able to run with less and make a file of the needed size
regardless, at the time of the dump, provided the headroom is there.

But I don't think a system in ordinary use should be set making these
major dumps - only if asked to by the developer of the code implicated.
They are going to be of no use to the ordinary user. There is an
argument for setting mini-dump, *if you are also setting to send reports
to Microsoft, for the statistical data base on failures - they are
useful in that. But that is something only broadband people will want
to have enabled, and in general I would have dumps off - and the boot
drive page file at 2 to 50 (which will probably not come into existence)
*if* the file is on a second physical drive

But the argument for a high maximum in any case rests on different
criteria - go read my article at www.aumha.org/win5/a/xpvm.htm. The
sizing of a swap file as a multiple of RAM defies logic on a system of
this architecture (it goes with multi-user Unix), and the size set by
system managed on a minimal 128MB machine is too small. While that on a
large RAM is grossly wasteful of disk space