Macs slowing network

[cneilson6]

Any ideas on this 1? Since we have come back after the holidays our filestore has been sat around 100% CPU and is causing major network slowness, we have identified that it is being caused by the Macs as we have stopped all students logging on too them and cpu usage has dropped down to around 5% with a few hundred users still logged in to the windows pc's. As soon as we log a classroom of macs on the cpu spikes even thought they are just sat doing nothing??

[chazzy2501]

MACs have a virus? or a virus scanner and or backup software scanning the remote store?

[bossman]

Could it be the Mac Botnet virus which has infected over 600,00 macs around the world to date?

 

Do you have an antivirus running on the Macs?

 

Have you just tried logging into the Macs one at a time to see if just one of them is the culprit?

 

Is it a Windows environment or X-server?

What are your thoughts on this?

[Chris_Cook]

Could you use netstat, wireshark or some other diagnostic tool to find out which macs are connected, and what they are doing? What are the mac users doing? Does it involve sending large files over the network? I would also echo the suggestions of installing antivirus software on the macs. Do you have network home folders setup on the macs, and are you mounting any network shares at login?

[Rozzer]

I had a similar issue like this on a network I support a year ago. It turned out to be bonjour on the macs for some odd reason. You can disable bonjour with a little hacking around.

[mac_shinobi]

I had a similar issue like this on a network I support a year ago. It turned out to be bonjour on the macs for some odd reason. You can disable bonjour with a little hacking around.

 

Was the bonjour thing related to the domain being a domain.local instead of a normal FQDN ie my.domain.org so bonjour and the domain.local were conflicting ?

[Rozzer]

If i remember correctly it was .internal domain. At the time I found it very odd and abnormally. Although when they had a whole network change I reenabled bonjour and the issue never came back...

 

Ross

[morganw]

Perhaps the home folders or some other resource is being indexed everytime someone logs in, hence the high load. What server OS is this and what protocol is used to connect to it?

[apeman]

Are your student mac home folders on this file server??

 

We have a very simliar issue with our macs, it turned out to be Safari and HTML5. Its uses a mysql lite database to track the equivalent to cookies in HTML5.

as soon as you open Safari we were getting thousands of read and writes a second per machine to this database which is stored in the users library folder, about 4 users was enough to bring our file sever up to 100% cpu usage. As soon as we disabled Safari and replaced it with Chrome the problem went away.

 

This might not be the same issue but its worth a look or use something like wireshark to see if you can find out whats going on

[Rozzer]

You could always enable cacheing temp files to the local machine instead of your network home drive. Also you could do a test by setting the one drives to force local instead of roaming.

 

Ross

[sjatkn]

As @Ross2k5 says forcing the cache folders to the local drive might help, it did resolve a similar issue for us. Originally we used Network Home Redirector scripts (NHR) when the clients were on Tiger, but now we are on Leopard / Snow Leopard I use MCX redirection (AFP548 - Leopard's Built-in Network Home Folder Redirector).