We have an Ubuntu file server in a small network that is serving about 8 Windows clients.
First, is it necessary to have a virus scanner on the server, or just rely on the clients (currently using AVG)?
If it is best to have virus scanning on the file server, what is a good scanner for a Linux Samba server?
ClamAV is generally regarded as a reasonable anti-virus. Although that said it doesn't have herustics (last I checked anyhow). It does however have on-access scanning.
Imho ClamAV would be the best choise.
Anti-virus on Linux systems really isn't required, the threats just aren't out there for it. However, if you can't get around the corporate mandate, follow Node's advice and just install ClamAV and a small cron job to do a periodic sweep of the system.
I also think Anti-virus is not really required on a Linux server, although it is best practice to have it, so you can say you do everything possible to keep things clean. There are exceptions where I would recommend an anti-virus on a linux server though.
Examples would be a mail server (you should scan attachments on your end, and incoming mail) or a file server with outside access (prevent your server hosts contaminated files). Not really for the safety of the server, but for the safety of your end-users getting their stuff off of the server.
ESET Antivirus (NOD32) have a linux version available. I've never used it, but the windows version of their software is excellent, and about the best I've seen as far as resource usage goes.
If all the clients are Windows, I'd certainly recommend installing some kind of antivirus software on the clients, since they're the most vulnerable.
I use ClamAV on my (samba) fileserver and (squid) proxy servers.
It's very easy to install and use and does a good job.
ESET Antivirus (NOD32) have a linux version available. I've never used it, but the windows version of their software is excellent.
I'm a fan of AVG Free for my Windows antivirus needs, and they had a linux client last time I checked. I used it for a bit since I use my server as a file server for my linux and windows clients.
ClamAV is good to ensure that your MTA doesn't propagate crap all over the world. This is good practice, it helps keep Windows users safe.
As for AV software on Linux, please read this koan. I strongly advise removing your shoes prior to reading the koan. It is Zen master teaching a Linux computer user who was used to Windows .. really funny.
I have some experience with Panda Anti-virus but not much. Seems to work all right.
I also found this article on linux.com.
It recommends: