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We have a fairly new server running Windows 2003 SP2, and the past few days we've noticed random slowdowns. When I'm logged into the server over remote desktop while this is happening, or if I'm physically sitting at the server logged in, suddenly everything becomes extremely laggy. Any UI element I try to interact with takes upwards of ten seconds to react, and then responds very slowly. Then a minute later everything is quite snappy again. During this, I have Task Manager minimized to the tray, and there's no CPU usage. I open it up right after this happens, and there's very little CPU usage on the graph, and no memory or pagefile usage above normal. (Normal being 1.5 GB free in the case of memory.) This is what I see logged into the server, and then users start calling saying things are slow, timing out, and failing--anything to do with our server.

No events in the Event Viewer around the times this happens. The context I'm working in (last thing I clicked, etc.) seems different every time--different programs active, different combinations of programs open. Never anything particularly stressful (like adding an event entry to a Cobian Backup configuration, or editing text in TextPad, which has been exceptionally stable in my extensive usage of it.)

I would've thought it was just the server, but a family member's home PC (entirely separate) running WinXPSP3 had the same thing happen to it last night a few times. Is this some new behaviour introduced by the latest Windows Updates? Either way, where do I even start to look when nothing seems to be chewing up resources?

Kev
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  • Have you checked your network utilization during these slow times? – Zypher Mar 04 '10 at 21:50
  • Oh, yeah, sorry, I forgot to mention that--network utilization is normal too, under 25% for the two or three spikes and otherwise near zero. – Kev Mar 04 '10 at 22:01
  • What is the server doing? Is it a file server or a IIS server, exchange etc? – Sim Mar 04 '10 at 22:23
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    What does your disk I/O look like when the lag happens (run a perfmon trace) ? – Zypher Mar 04 '10 at 22:38
  • I finally caught a perfmon log while it was lagging...the disk I/O averaged (including the part of the log not during the lag) 5 times higher in terms of write ops/second (83) than a shorter I took while no lag occurred (16.6). – Kev Mar 05 '10 at 14:59
  • @Sim, it's a low-traffic internal file/AD/web/db server. It's replacing one with half the CPU/memory resources that was adequate before. – Kev Mar 05 '10 at 15:34
  • Kev: The I/O wait is more interesting - raid controllers (if you are using one) queue up scsi commands while waiting for disks to finish writing/reading, or in the worst case: reiniting after failure. – pauska May 10 '10 at 22:08

4 Answers4

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I'm thinking something to do with the network or Internet for this issue since you say CPU, Mem, and Page don't seem active...

Check your Windows Update settings for your server and home user on XP. I notice on my system at home that if updates are set to automatically download that when they do download sometimes the system really lags until those downloads finish.

If that doesn't seem to help, check for NIC activity. I'm not sure what a good method for doing this would be. You can run Performance Monitoring and when the system seems slow check NIC activity in that. If you see spikes during lag times, you could then do a capture with Wireshark to see what traffic is going out/in of that server.

If both of those don't seem to help, I'm not sure what else you could check for. Faulty hardware somewhere along the line would be my next guess.

Webs
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  • WU on the server is set to manual at the moment. Thanks, I'll check out Wireshark. (I hope it's not hardware! We just got this box... :-| ) – Kev Mar 04 '10 at 22:08
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Have you maybe got an over-zealous anti-virus doing some on access scanning of a large file somebody might be accessing/saving?

It could also be slow disk I/O - what's the server doing, and has it got anything installed that might be saving large files or something similar?

Process Explorer is absolutely fantastic at getting a quick view of CPU, memory and disk activity.

Ben Pilbrow
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  • No real-time AV, just scheduled after-hours ClamAV at this point. I don't think the server's doing anything out of the ordinary, just its normal file/AD/db services. I was thinking of Process Explorer, except that it can chew up RAM if you leave it running too long, and unfortunately, by the time the system is responsive enough for me to actually launch a program, it's too late. – Kev Mar 04 '10 at 22:21
  • One would think an AV scan would generate CPU and at least Mem usage. – Webs Mar 05 '10 at 13:14
  • Oh, I was thinking of ProcMon. I'll give PE a shot. – Kev Mar 05 '10 at 13:44
  • Sometimes I can get Cobian 9 to take up 25% for brief periods, and during this it seems pretty laggy...but it has happened without Cobian open before. – Kev Mar 05 '10 at 15:09
  • (BTW, that's not during a backup, that's just editing the configuration.) – Kev Mar 05 '10 at 15:23
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Was digging around for an answer to the same type of thing. Nice fast server but took forever to pull up anything (especially related to AD), users complaining of "Exchange is attempting to receive data" type messages, and with no server load at all.

Found another article that pointed to DNS. Sure enough, primary forward lookup was the PREVIOUS server which no longer exists.

Deleted that entry and bam. Snappy again.

Now when I pull up a user account out of ADUC it happens in less than a second as opposed to 5.

Not the first time I've heard that DNS is everything on a server.

Hope this helps.

(2003 SP2 here also, btw)

  • This is certainly possible, since we just transferred from our old server. But everywhere I've looked I've already removed references to the old server. In DNS->(server)->Properties, checked every tab. The only remaining references are its Pointer and HOST(A) records in the reverse and forward lookup zones, but that wouldn't be enough to do anything, would it? (I left them there so I can still boot up the old server if I need to look at how something was configured.) – Kev Mar 05 '10 at 13:29
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I'm also having this issue with 2 of my servers. The first server was just a file\Print server running 2003 R2. it was on a Dell 2900. orginaly I thought it was the hardware. so I rebuilt the server on another 2900 and moved the dataover. the problem was still happening. The way that I see the problem is to do a dir /s on a large volume. for me it's D: when the scrolling of files and folders lags is when everything else is lagged.

For that server I ended up putting 2008 Sp2 on it and the problem went away. Now I'm hainvg the problem on a Hyper-V 2003 instance. The users report the lag when they do file operations on this server. There home drives are mapped here. They will click on P:\ and wait about 10 to 15 seconds

Christopher Thornton
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