[SunHELP] 2-host filesystem mount?

[David Strom]

We have a situation where we're thinking of mounting a LUN on our SAN to 
2 hosts, where one would have a writeable filesystem & the other 
read-only.  Would save us having 2 copies of the same data.  Right now 
both Sun servers are running Solaris 9.

If the writing host puts all the data on the filesystem, then the 2nd 
mounts it read-only and there is no change, no problem (we think).  But, 
if the 2nd RO host has accessed a file recently so it's cached, and the 
1st RW host modifies the file, and the 2nd RO host gets another request 
for that file, how does the 2nd system "know" the file has changed? 
Sorry for such technical terminology. ;-)

Has any one tried/done this?  Successfully, or not?  We don't have 
budget $$ for commercial cluster software, and really don't want to do 
that, anyways.  TIA, as always.

--
David Strom