I set up 10gRAC at a previous job a couple of years ago on RH Linux; also had some experience with 9iRAC (using raw devices for individual datafiles - yuk). We used ASM and it worked ok. Initial setup was an issue, at first tried to use asmlib but there was an incompatibility at the time with the EMC storage we were using, so instead just made one big raw device out of the storage lun devoted to the database, and set up ASM on it. You may also want to look at the cluster file system from PolyServe (used to be an independent company, but since bought by HP). Many of their people were from the old Sequent. (Kevin Closson, a prominent Oracle blogger, worked for them, and still works for HP I believe). As far as GFS, I seem to recall an issue with GFS about needing more than 2 nodes in order to work properly, not sure if that is still an issue.
Note that you need 3 different Oracle Homes in 10gRAC if you use ASM; one for ASM, one for Oracle Clusterware, and one for the traditional Oracle binaries. One of those should NOT be set up under ORACLE_BASE (can't remember which one, I think it was ASM). It's mentioned in the doc, but not very prominently.
Hope this helps a little.

4  out of 5 found this valuable. Do you find this valuable? Do you?