Still no luck I'm afraid.
"showmount -e" showed me I needed to start the NFS server (oops) which I did by hitting "Activate" in NFS Manager, and now it says:
	Code:
	[b]/Users/williamr:[/b] showmount -e    
Exports list on localhost:
/Users                             10.0.1.100 
 10.0.1.100 is the CentOS VM. I interpret that as saying the Mac is granting 10.0.1.100 access to /Users.
Also while double-checking I realised that the Mac is at 10.0.1.2 (10.0.1.1 is the gateway), so I changed /etc/auto.home in CentOS, switched off the Mac firewall (CentOS is running without one) and restarted CentOS. No change.
Reading the man page for nfs, it says I should put an entry in /etc/fstab. Could I be missing something there, or does the "auto" thing take care of it automagically? My /etc/fstab in CentOS looks like this:
	Code:
	# This file is edited by fstab-sync - see 'man fstab-sync' for details
/dev/VolGroup00/LogVol00 /                       ext3    defaults        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /dev/shm                tmpfs   defaults        0 0
none                    /proc                   proc    defaults        0 0
none                    /sys                    sysfs   defaults        0 0
/dev/VolGroup00/LogVol01 swap                    swap    defaults        0 0
/dev/hdb                /media/cdrom            auto    pamconsole,fscontext=system_u:object_r:removable_t,exec,noauto,managed 0 0
 Looking for troubleshooting tips for nfs I found http://www.troubleshooters.com/linux/nfs.htm (although this isn't about Mac or CentOS specifically) which gives a "mount" command like:
	Code:
	mount -t nfs -o rw 10.0.1.2:/Users/oracle /macshare
 I tried that as root (with the Mac's firewall off) and it failed instantly with mount: 10.0.1.2:/Users/oracle failed, reason given by server: Permission denied", which could be telling me something. With the Mac's firewall on it hangs for a while then fails with a timeout error. I tried putting the firewall on but enabling all the listed options but the CentOS side always gets a timeout. I tried mounting different Mac paths (/Users/Shared, /Users) but it made no difference.
There must be something different between our setups, but I'm running out of ideas.