Server hardware specs, performance question?

[Lando2]

Our mail server is a 4x500Mhz P3 Xeon with 2GB Ram, it has a 4GB page file.. It holds about 15,000 exchange mailboxes with about a maximum of 500 people using it at any one time.

According to MS specs, this machine is well over spec for handling the load, yet during peak hours it's so god damn slow... It took maybe 40 mins the other day to copy 30MB of messages to another folder.

Are there any tips or tweaks for memory usage to increase performance for the store and other services? Once rebooted the server takes about 2 hrs to load the store fully into memory.

Would adding another 100mbit network card help? (as someone mentioned this, but I dont see it myself)

 

[Zelandakh]

You need to run perfmon as a priority and find your bottleneck.

Had you got NT4 I'd have pointed at your pagefile which should be 2GB. Under 2000, it may still be your problem. With the amount of requests you must be getting, I'd say you have some key areas to check:

Disk queues - are your disks quick enough?
Network - You could probably benefit from either a second network card or a gig NIC.

Pick some useful stats from perfmon and you'll find the bottleneck fast enough.

 

[Lando2]

Hmm I dont really know what I'm looking for, they all seem normal to me.

Here's a few figures (averages):

% CPU time: 19%
Memory, Pages/sec: 270
NIC - Bytes/sec: 320,000
Disk - Bytes Trans/sec 30,000

All seems pretty low.

Maybe its the disks having Raid-5 that are making things slow.

 

[Zelandakh]

Memory pages/sec - aren't they supposed to be below 40? 270 seems very high.

 

[Lando2]

Thanks, but is there a tech site that varifies `that they should be below 40`? As I dont really wonna go buy another 2GB of ram and find it makes no difference.

Trouble is, we haven't got another loaded server to compare it to.

 

[ACraib]

From what I remember of my NT4 MCSE revision having page/sec above 20 means you either need to increase your memory of the speed of your hard disks.

 

[Lando2]

Anyone explain why slower hard disks would make more page file accesses per second? I'm a bit stupid

 

[FilthPig]

It wouldn't make more page file accesses, but it would make those accesses faster. Marc Creviere

 

[FilthPig]

Er, slower. Marc Creviere

 

[Lando2]

Surely then my pages/sec would increase if my disks were faster??? Im confused...

Luckly I've just been booked up on a Optimizing & troubleshooting win2k course... I'll fire these questions at the MS trainer

 

[FilthPig]

You should still have the same number of pages/sec, but each one would execute faster, resulting in increased application performance. (In theory anyway.)

However, more memory would probably be a cheaper and easier route to go than replacing all your hard drives with faster ones (All drives in a RAID 5 array must be the same size and speed). Either that or find out if there's anything eating up memory that you don't need. Marc Creviere

 

[Zelandakh]

I haven't got my NT4 notes whicch would have confirmed this. All numbers are ballpark ones anyway but I thought pages/sec above 20 meant add RAM. It might have been HD access issues.

It was something you needed to know for the exam but that was years ago

Read up on perfmon and check the MS web site - you never know it might help LOL

 

[Lando2]

Well I've been keeping track of available free memory, and it seems to have about 500MB free once all the store is fully loaded and other services, so I dont think it's the memory. Page file usage is only about 3%.... So all that is left is disk speed.

 

[FilthPig]

Or, it may not be a hardware problem at all. Are you current on your service packs? Marc Creviere

 

[Xybertron]

Are you running Win2k Advanced Server? If not remove a GB of Ram. I could go more into detail but won't unless you ask Here is a Q so you don't think I'm full of sh!t.

XGEN: Exchange 2000 Requires /3GB Switch with More Than 1 GB RAM
ID: Q266096 Dan
Microsoft Exchange Support @ Microsoft

 

[Lando2]

The server in question is Win2k Advanced, 4xXeon500's 136GB Raid-5 Disks, 2GB ram.

All services packs are upto date (run windows/update), it's running on a 100mbit, full duplex.

What do u mean by /3GB switch?

 

[Zelandakh]

he means running the exchange service with a command line switch.

 

[Lando2]

Ah, great, the switch wasn't there, so maybe it'll work ok now and not slow down after a few days.

Fingers crosses.

 

[Zelandakh]

The other option is to take Xyber's word for it (and if he says you should try it, you should) and take the RAM out.

 

[Xybertron]

Nah if you have Advanced Server and the /3GB as documented in the article you will be ok.

I've "seen" that we try to use over our 2GB Virtual Address Space thus hitting a brick wall and causing store issues that make it look slow. This fixes it as seen in a perfmon if you monitor Virtual Bytes of Store. This is under the Process set of counters. Usually over 1.5GB in non /3GB scenarios is when you see the issue. Remove ram or upgrade and use /3GB switch.

If you have the problem again just message Dan
Microsoft Exchange Support @ Microsoft