Nfs
Some NFS “issues” .. /me rants about RHEL 4.. reboot fixed it.
[Gentoo Prefix][1] allows you to place a “prefixed environment” wherever you would like. So, if you want to be able to access your prefix on a NFS network it would make sense to put the prefix in /home for example. I don’t have any solid numbers but I can imagine that the IO for the nfs server is pretty high when emerging. I would rather not suffer the penalties of compile on NFS but also I WOULD like to access PORTAGE_TMPDIR from any host.