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Help with understanding Page File Usage

Hi all.
I have read many posts 'round here regarding Page File Usage, but I am sometimes confused by the numbers and the math behind them.

I am running Windows Server 2003 Enterprise (32bit).  Hyper-Threaded Dual 3.0 Xeon, 8GB RAM.  (4) 750GB Seagate 7200rpm SATA drives.

I have Exchange 2003, my store.exe shows at about 600mb of RAM usage.
I have Symantec Corporate AV - which when it scans shows a number of high-use RAM figures.  I know it's a memory hog but it's what I have to deal with right now.
I have ACT! (which runs an instance of SQL 2005 Express).
I have BES server.
This machine is my DC, AD, basically it  is everything to my office.

And it has been running sluggish.  I get pop-ups all day on client machines about "conection to MS Exchange" going in and out (not sure if that's related - but it seems to be based on reading I have done here on EE).

My CPU usage runs at under 10% most all the time I ever monitor it.

My Page File Usage is 2.94GB.  And I don't know whether that is high or not based on my RAM and what I have going on.

So, I am throwing this one out there to see who can help explain this to me and give me any recommendations on what to do or if i should be doing anything.  If there are gains to be made in performance I may give them a try, but if its not really worth it and there are other issues I should be looking into, then I can at least stop wondering about this.

(I am aware that I need another box and that it would be ideal to get Exchange and BES off this one - but that is another topic for another post I have out there - and for me to try and convince my boss to give me the budget to do it.)

I am sure there are questions - and if screenshots are necessary let me know.
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4 Solutions
QlemoBatchelor, Developer and EE Topic AdvisorCommented:
With 32bit OS, each access above the 4GB limit is done by address windowing, which means that parts of extended memory need to be mapped into the 4GB area. Of course this has influence on memory performance.

As you have a mem usage of ~3GB, this could be the  case now. The OS is seeing more memory, and trying to use it (for caching for example).
This is only a guess, you would need to see whether real paging is taking place. However, with a slow responsive system with enough CPU power, the I/O subsystem, memory or other "peripherals" is the culprit. With 4 SATA drives, and as I hope balanced disk access over all drives, they should not be the bottleneck.

For a first attempt, I would use perfmon with monitoring top processes' memory consumption, and drive access figures. That should give you an idea where to search next.
I would also monitor disk usage, with all those apps running on the same box I would have a feeling you could have issues there, especially with the AV which can really slow things done. How many users are you supporting on this system? 7200rpm drives aren't so hot if there is a lot of disk activtiy,

here's a link discussing perfmon stats for sql, it is applicable to your overall system though:
Something that will speed up pagefile usage: Make the pagefile have a fixed size, for example 4GB-4GB in the page file settings (My Computer properties). If it sometimes is over 4GB you can make it 6 of 8 just to be sure (if you have enough diskspace leftover).
After that, close as many programs as possible, disable the virusscanner and defragment the harddisk, this steps will speed up the pagefile usage as the pagefile 'file' has no need to grow any further (and get fragmented) because there's plenty of swapspace leftover.
Also getting faster disks (as phead_2 suggests) will speed up the pagefile, it can be an idea to put the pagefile on a single fast disk (15k SAS 36GB or something like that) to speed it up.
If possible move to a 64bits OS, this will increase the memory limit so you can put 8GB or more in a machine. Also it can be handy to setup a second server and split the tasks, this will also make your network more redundant if you set it up as a secondary domain controller. Virtualization can also be very handy in situations like this, using a single powerserver running ESXi.
Good luck!
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Here is a pretty easy Solution;
 Your paging file on %systemdrive% needs to be Double the memory. and should be contigous.

Defrag all drives
Create 16gb PageFile (MyComputer / Properties / Advanced / Performance)
   on all 4 drives
drop pagefile on %systemdrive%
 (warnings here about dump files)
Defrag %systemdrive%
Recreate new pagefile on %systemdrive%
Have a nice day :)
QlemoBatchelor, Developer and EE Topic AdvisorCommented:
>> "speed up pagefile usage: Make the pagefile have a fixed size"
>> "Your paging file on %systemdrive% needs to be Double the memory"

That's common believed nonsense. Having a fixed size pagefile is a good idea IMHO, but the prevention of fragmentation results in a performance gain in the one-percent area.

And "double the memory" - are you crazy? A 16GB pagefile is not useful in any case.

The more real memory you have, the less pagefile you need. Going over 4GB total of real memory + pagefile does not improve speed with 32bit OS. Most server applications will look for available memory, and calculate their memory allocations based on the figures. If they think there is more memory, they might want to use it.

Don't forget - paging is very slow process, physical memory has a access time of nanoseconds, while disks are at milliseconds - that's a million times slower.

Windows tends to page out some memory, even if not needed to do so, and that is why you need a pagefile even with 8GB. But I would keep it small, 1GB should be enough.

One point is a good one - to distribute the pagefile over several disks. Windows will prefer to use that pagefile which is on the least active harddisk. If the pagefile is used extensively, this could give you a speed burst (10% maybe).

mmoroccoAuthor Commented:
Hi all:
WOW - ok - so this all sounds interesting and useful.  Some of it I admit is over my head a bit.  I am a self-taught guy with a PoliSci degree trying to study at nights to learn and hopefully start working on some certifications soon...but anyway...thank you.

I thought I'd throw these two screenshots up.  The PF Usage is from yesterday afternoon.
The Performance screenshot is a few hours ago when I was in the middle of importing a rather large PST.  Otherwise it was a rather normal afternoon, which is usually our busiest time of day.  But I had a moment and looked at the performance and said, Whoa!  The EE gang has to see this!

I am running RAID-5 across the 4 750GB HardDrives.  I have since learned that this is not ideal for Exchange, like having it with the DC.  But I had some help setting up this network a few years ago and went with people's recommendations at the time - and I only had one server.  So I have what I have...I have other posts out there where i described my network and environment in detail and am looking for ways to revamp and make best use of what I have, being a few years worth of experience smarter than I used to be...If anyone cares to help let me know and i will give you QuestionIDs.

--I have about 7-10 desktops/users in the physical office where this server is on a daily basis.  Mostly running Office locally, accessing files from the server, nothing intense to speak of.  
--I have 2-3 remote users.  I work remotely, and run on average 2-3 RDC sessions throughout the day.  I am on a VPN tunnel with the office between 2 Sonicwalls.
--I only have 1-2 users who access ACT! throughout the day consistently.
--We do a fair bit of Scanning to PDF to the server - the pdf is made by the copier and then just sent to a network drive, the server is not converting anything.
--I have about 2 dozen mailboxes in Exchange2003, and about the same amount of Public Folders, some mail enabled, others which are just filing cabinets.  We also use Public Tasks and Public Calendar.
--I have 3 1U video encoders that capture MPEG-1 and write to the server (this is only on a job-by-job basis - this does not run all day everyday).
--I have DFS replicating Exchange to a server here at my location, as well as a few network folders that i like to have backed up.

Hopefully that is a little more info on my environment that may help.  I think that is most of the major stuff, and so without complicating anything by asking more questions, i will leave you with that knowledge and see what you have to say - if that affects or changes recommendations.

And to comment on what was said above:

Qlemo - I would like to know more about how to make best use of perfmon to do what you suggest.  I did have to enable the PAE switch when I first setup my server.  How do I "see whether real paging is taking place?"

phead_2 - yes, i have since learned that my drives are not so hot.  I wish I knew what to do about it, because swapping them for new ones really isnt an option I dont think.
It was the Avg Disk Queue Length spiking in Perfmon and the popup balloons about my Exchange connection dropping and restoring constantly that led me to posts here on EE about RAID5 and Exchange and 7200 SATAs not being so hot.
Thanks for the link!

JapyDooge - Yes, I would love to move to 64-bit.  And I would love to buy faster disks.  But based on my environment and the resources I have to work with - this leads me to basically buying another server.  Which I am trying to work on my boss about...And then maybe I repurpose or rebuild this one up to better specs...or use itfor virtualization or it becomes a backup...

To JapyDooge and Banthor - I guess I must have been getting bad info - but I always thought you werent supposed to or didnt need to Defrag a server - especially not one running Exchange.
I would like to hear more about this.
As for increasing and recreating the Pagefile and etc - if its as easy as you make it sound I will give it some thought...

Qlemo - you came back and refuted some info - if you have more to say based upon this new info I would like to hear it.  And more info on this pagefile move you suggest would be appreciated.

And so a simple question that I think I know the answer to:  Would more RAM help?  I know I am stuck with 32Bit - but with Enterprise arent I supposed to be able to support and get the benefit of even more than the 8GB of RAM i have now?
I know my HardDrives are slow and I have alot going on on this box, but is more memory even an option or an answer to any of this?

thanks in advance for your time in reading this and hopefully responding...

i think you're better off getting another box rather than switching to enterprise. I know the costs aren't quite inline but i would think if you have the $ to buy enterprise you could spend some more to get another server.

There's a reason why you're not recommended to run things like BES and Exchange or Exchange and SQL, etc. together. At some point it becomes too much.

Also, since it hasn't been mentioned - are you sure you've setup your AV scanning properly for the various services you running. Not only can it really slow things down in general but if you trying to scan  sql db files (ACT), a lot of the exchange files (don't know what verision you're running), etc. it can make it a lot worse.
mmoroccoAuthor Commented:
Sorry for any confusion - but I AM already running Enterprise, which is why I bought the 8GB of RAM, and asked about whether more would help.

No, I cant say I have checked into my AV scanning functions.  I dont know enough about exchange yet to know what to include/exclude.
I can exclude the ACT files easy enough myself I am sure.  I had a 3rd party IT company help me with setting up the Exchange 2003 and Symantec 10.1 originally, so I dont know for sure how much config they did towards this.

But yeah, I know I need a new box, and am working on it, I would like to move to Win2k8 and Exch2007, and put them alone on their own box with nothin else...which would really then free up this box to do what it can and i think it would prove pretty worthy and useful then.

BES and Exchange on separate boxes??? I thought they were meant to go together?!?
"BES and Exchange on separate boxes??? I thought they were meant to go together?!?"

This is not officiallly supported by blackberry, see page 18 of the install guide (4.1 SP6).
Setting the page file on the %systemdrive% at double the memory is a best practice since Win2k.
The performance gain is felt when Exchange, SQL Server, and TerminalServices are in use running and runing under user accounts/profiles.

but since we have a 4 disk raid it is all Moot.

Please test the Raid array for any bad disks first.
Make Very sure the Raid is fully operational. There are circumstances where windows wil report the raid as funcitonal
But one disk is actaully lagging and useless, but detected.

If it's broke, theres the fix.
If not - then you have officailly out grown your server.


mmoroccoAuthor Commented:
Thanks for such quick responses!
I realize I never uploaded the screenshots.
here they are - if they help any.
Here's a link to a very basic overview of some perfmon stats and what they mean, you should review it. At any rate it looks like pages/sec and disk queue length are high. Of course the first can cause the latter. While you may able to make some adjsutments (I still think faster disks with a better setup would be the best thing you can do) ultimately it's just time to lighten the load on this box.

QlemoBatchelor, Developer and EE Topic AdvisorCommented:
W2k had a different memory management mechanism, since XP many things were changed, like paging registry, handling of memory above 4GB and many others. You can't compare W2k best practice with W2003 that easy.

the RAID array is the issue. Disk queue length should not increase above 6. With a max. of 37 (!) and an average of 5, this is much too high. The scale for disk queue length is to big, so we can't see the exact figures, but I guess the I/O subsystem is busy writing all the time. We cannot see if there are peak writes, though.

In RAID 5, writing is costly. Each time a block is written, the corresponding blocks on all disks have to be read for calculation of the XOR mask, and that mask is written to another disk, adding to the overhead.
Windows does not know of all that, it sees only that the disk driver can't execute disk requests immediately, and queueing them - that is what we see in perfmon.

Again - your memory is not the problem at all, you are using ~3GB, which is ok, and VM should be reduced instead of increased. 5GB are used for caching - that is ok, however, it is a sign of heavy file operations.
Actually my experience with paging files was on campus at microsoft working on server 2003 enterprise servers in the extranet.

A functioning RAID array writes the same, a failing array works better than a failing disk, but not by much.
Please carefully test your array first!
But hardware is on the horizon. Not just disks, but spreading services out across other hardware.
mmoroccoAuthor Commented:
I would really appreciate some info on how to Test my array.  Do I use (and do i trust) the Intel application that came with my controller?
Is there a utility any of you recommend?  Sounds like perhaps the Windows OS is not to be trusted here.

To all of you who have told me what I know, which is - as Banthor put it - hardware is on the horizon, boy, do I know it, and I sure hope so...I am working on configs and pricing now for a box that I can hopefully get past my boss, even if we have to lease it, which I dont think is such a bad deal if you can trade-in/trade-up in 3 years...

So how do I check/test my array.

And whether or not it will really help performance - CAN you really just run a Defrag on a Giant RAID5 volume?  I would do it, and probably do it often if I knew it was ok, but I was told this was either a no-no, or not necessary...?
As for defrag it depends on the OS, Installation and the Raid Hardware and Software.
Better systems really don't need it unless you are doing a Lot of Medium file creation and deletion on disks that are very close to full.

If windows is managing the raid, then windows defrag should should be accurate.
, but an OS Raid suffers other performance issues as well that could be your problem.
Based on your comments windows sees the Raid as a single Primary Disk.
SO, Consult the manufacturer.
DID I read that you had checked that the BIOS is current?
I found several dell motherboards that required BIOS updates or Windows 2008 had issues.
mmoroccoAuthor Commented:
Hi to all - didnt want this question to get listed as abandoned.  I hate to leave open questions - but I ma not through with this yet, so I will be in touch after the holiday sometime this week with an update and probably a few more questions...
mmoroccoAuthor Commented:
Hi again all - am simply swamped and trying to come up for air.
I am going to take to heart and mind all that was said here and hopefully soon be able to give it the attention it deserves.
In the meantime I am working on a proposal and a couple of configurations of server for possible purchase that I am going to put in front of the boss soon.
The real solution as I knew from the start is to "lighten the load" on this box, get Exchange off of here and onto a box that is optimized (disk speed, RAM, proper RAID) for it, and if that box can handle one or two other duties so be it - but just relieving exchange from here i believe will make all the difference...
So, I apologize if I have not thanked or responded to each of you for each of your points/advice, but I do thank you.

I have received "help with understanding" as I asked for in my subject, and that is great. I am wiser for asking this question.

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