Hi futare,
let me try to answer your questions below:
1. What Linux distro's are supported? Can I use Fedora or should I use RHE ? Anyone have any experience of using other distro’s?
If you install NSM on your own server, only RedHat or Solaris are the supported OS.
Watch out the VMware is not supported!
2. What size disk space should plan for? I know this is kind of impossible to answer but some experiences and "guesstimations" would be much appreciated. We would like to retain about 3 months worth of logging information (1 month minimum online).
You can find this in the Installation Guide:
http://www.juniper.net/techpubs/software/management/security-manager/nsm2008_2/nsm-installer-guide.pdf
Check Appendix B
3. Where to put the NSM. There is a small topology diagram that came packaged with the software that suggests it should be placed in a DMZ Zone. Can anyone shed some light on this?
It would be better to have NSMplaced on a management network with direct access to the management interface on the devices.
This way you have a separate network for the management where only the network/security admins have access.
You can call this DMZ, or just management network separated from the rest of the netrowks.... 🙂
Hope this helps!
Ciao 🙂
Daniele