[Diego8]

Hi. I have been dealing for a while (since day one) with this issue that's making me pull my hair out. This is the scenario. We have a desktop computer that acts as a file server. It runs Windows 2003 Server with Active Directory, Domain Controller and DNS Server configured.
Most of the clients run Windows XP Professional (joined to the domain) and a few run Windows XP Home.
Clients can access the server's shared files fine but sometimes after browsing some files (opening and closing different files) the Explorer's Windows comes to a halt (the title bar changes to "Not Responding" and the sand clock appears).
Sometimes after a few minutes the explorer starts responding again but in other cases i have been waiting and waiting (more than 10 minutes) and the window is still not responding so i have to reboot the computer or reboot the server which is really annoying.
I have browsed the events log in the server and no error or warning are logged when the connection "dies".

Any help would be greatly appreciated.
Thanks.

Edited by Diego8, 06 August 2008 - 06:59 PM.

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Windows Server operating systems has Client Access Licenses (CALs) that determine how many simultaneous connections it can support at one time. Are you sure that your client computers are not exceeding the number of connections that your CAL supports?

Edited by Mobious, 06 August 2008 - 11:32 PM.

[Mobious]

Windows Server operating systems has Client Access Licenses (CALs) that determine how many simultaneous connections it can support at one time. Are you sure that your client computers are not exceeding the number of connections that your CAL supports?

Edited by Mobious, 06 August 2008 - 11:32 PM.

[dsenette]

i'd more likely point to an "under powered" server machine...if this is a desktop computer running AD, DNS (i'd assume DHCP) AND it's being a file server....then you're going to need it to be a pretty strong machine....it's ALWAYS best practice to not have ANYTHING but DNS and active directory on the DC...you can get away with running DHCP there as well...but domain authentication takes up a surprising amount of power

[Diego8]

Yes, it´s a desktop computer that has a Pentium D CPU with 3.2 Ghz and 2 GB RAM.
From what i see in the task manager, so i guess performance is fine. CPU usage has some peaks (50 or 70 %) but not for more than a few seconds. Free physical memory is always above 1 GB.
I´m writing this while i´m checking this numers. Right now the server has 5 users connected to it.
Server runs AD, DC and DNS. It does not run DHCP (desktop client computers are configured with Static IP). The DHCP server is running in our firewall (Cisco Pix 501) only for those (3 or 4 laptops) that connect to the server wirelessly.
If performance is the problem, would i see a 100 % CPU usage on the server while the client´s explorer is not responding?

Some laptops run Win XP Home, which is not able to join a domain. These clients get an IP address form the DHCP server. I have seen that the DNS server does not register them since they don´t login to the domain.
Could this be causing the issue?.

Is there something else that could be causing this?.

Thanks.

Edited by Diego8, 07 August 2008 - 05:25 PM.

[Diego8]

thanks for the hint Mobious. I didn't know Windows Server had that kind of licensing. I've been googling for this but i couldn't find the way to know how many CALs a Windows Server has.
Ours is Windows Server 2003 Standard Edition.
Is there a way to find out how many CALs it has?

Thanks.

Edited by Diego8, 07 August 2008 - 05:37 PM.

[Mobious]

You can get information about CALs in Control Panel > Licensing.

[dsenette]

i think something needs to be cleared up here...microsoft's server licensing is one of the MOST confusing things i've EVER seen....so it's hard to grasp sometimes

in a windows domain environment you're required to have a CAL for each user OR device (you can get user CALS or device CALs...the difference is whether or not you have multiple users on each machine etc.. and some other funky metrics)...but this is a licensing requirement for if you get audited by microsoft....the licensing module that mobius is talking about is actually relatively separate....IF YOU CHOOSE to enable the licensing server on your DC (or any other server) then it will track the amount of licenses you claim that you have (it actually has no way of knowing how many you've really purchased)....it STILL won't control connectivity to your servers...it will just give you a way to know if you've passed your limits.... there is a "concurrent connection" limit on server 2003 but this applies to terminal services (remote desktop to the server etc...) and not file access....there's no real restriction on how many people can access files on a server other than physical limitations of the server hardware

each instance of server 2003 comes default with 5 CALs that can either be assigned as user CALs or Device CALs

[Mobious]

in a windows domain environment you're required to have a CAL for each user OR device (you can get user CALS or device CALs...the difference is whether or not you have multiple users on each machine etc.. and some other funky metrics)...but this is a licensing requirement for if you get audited by microsoft....the licensing module that mobius is talking about is actually relatively separate....IF YOU CHOOSE to enable the licensing server on your DC (or any other server) then it will track the amount of licenses you claim that you have (it actually has no way of knowing how many you've really purchased)....it STILL won't control connectivity to your servers...it will just give you a way to know if you've passed your limits.... there is a "concurrent connection" limit on server 2003 but this applies to terminal services (remote desktop to the server etc...) and not file access....there's no real restriction on how many people can access files on a server other than physical limitations of the server hardware

A Windows Server operating system cannot operate properly without a CAL. It cannot perform its server function without a CAL because no client can ever consume its services. There is also no seperate CAL for servers running as a Domain Controller. The CAL that I am taking about is for the operating system itself.

The licensing of Windows Server 2003 is based on general access instead of service access (eg. Domain Controller Access). So for short, all authenticated access to the server (eg. File Sharing) requires a CAL. Any connection that includes an exchange of Windows Credentials takes one CAL

For more information see: http://www.microsoft...003_server.mspx

[dsenette]

correct.....on paper...it's not a physical restriction...you're required to have on file the amount of CALs that you have purchased to cover the amount of users/devices that are going to obtain server access....HOWEVER the server itself will not deny access to resources past that number (UNLESS you are actually running the licensing server which is NOT a microsoft requirement)

programs like spectorsoft (a monitoring program) have a license structure where you input a license file that dictates how many licenses you've purchased...once you reach that number the program will not allow you install another instance of the client UNTIL you free up a license....

microsoft's server access licensing doesn't work that way at all

[Mobious]

You need to purchase Windows CALs for the maximum number of simultaneous connections to that server. Any device or user can access the server, but the number of simultaneous access connections hitting the server at any given time must not exceed the number of Windows CALs designated to that server.

Yes, it is a physical limitation.

For more information see: http://www.microsoft...g/overview.mspx

[dsenette]

right.....on paper the number of simultaneous connections cannot exceed the number of CALs you've purchased


this is not a dig or knock on you and it's not meant to be confrontational but it may sound that way because of the wording but

do you have a large scale domain environment at your disposal? are you quoting this information from the MS site without actual usage knowledge?

i'm managing a VERY large scale domain environment so everything i've stated in this thread is based on factual observation of a LIVE system...and i can assure you that your servers have NO KNOWLEDGE of the amount of CALs you've purchased and impose no limitations on connections based on that number (unless you SPECIFICALLY TELL THEM via the licensing server supplied with 2003 that is OFF by default)

[Mobious]

OK, I get your point. I cannot just simply state that my argument is correct without the presence of a premise. My knowledge of Windows Server 2003 as a student is no doubt much limited than yours. However, I will try perform an experiment at our lab to simply check if the number of CALs limit the actual number of simultaneous connections on a single server.

[dsenette]

please do....again i'm not trying to be argumentative or tell you that you're flat out wrong...i'm just stating things as known on a live environment (namely my environment with 12 servers and about 200 users)....believe me when i was in school for this stuff the licensing was one of the things that i never fully understood...and to be quite honest it still makes my head spin sometimes at work...the MS licensing structure is funky at best...and in a real life situation it would make everyone's lives that much easier if their licensing DID work the way that other software licensing works...where it would actually require the license to be there to facilitate a connection

but i can tell you that at the moment none of my servers physically know about any CALs above the original 5 that the server shipped with (as default with the OS) and i've got MANY more than 5 simultaneous connections at any given moment

[Diego8]

Oh. I´m catching up with the replys now.
So, according to dsenette, if the license thingy is turned off the "CAL restrictions" will not be an issue. Right now i´m not sit at the server but i believe this was never configured.
So, CALs wouldn´t be the cause of the issue, right?.
If CAL is the cause, wouldn´t i get a message saying i reached max connections or something like that (instead of the annoying "not responding" explorer window)?.

Also, the not responding thing happened, a couple of times, while only one or two users had their workstations turned on...

Thanks.

[Diego8]

One last thing i forgot to say. Some ethernet cables (from the workstations to a switch) are quite close from power cords.
Although most cables (including the one from the main switch to the server) are at a proper distance from power cords, could EMI be blocking the whole network?.