This is not a gentoo-specific question but please bear with me. The computer center I run has a fairly large beowulf cluster, a set of database servers, and several other specific-purpose servers for a total of around 175 systems. Currently there are a half-dozen servers with local raid arrays used for home directories, which are NFS-exported and mounted via autofs with LDAP tables. For a variety of reasons, I am getting several iSCSI arrays and some of the directories on the file servers will be migrated to these arrays. However, a few of the direct-attach raids will remain as such. The iSCSI arrays will have OCFS on them and will be mounted on most if not all of the servers. What I am looking for is a manageable system of handling home directories. I see 3 different scenarios that need to be handled.
Case 1: A home directory is directly attached to hostA. If the user logs into either hostA or hostB, the directory should be automounted. Case 2: A home directory is on an iSCSI array mounted on both hostA and hostB. When the user logs into either of these systems the home directory should be automounted directly from the iSCSI mount. Case 3: A home directory is on an iSCSI array mounted on both hostA and hostB but not on hostC. When the user logs into hostC, the home directory should be automounted from one of the other two hosts. I could probably avoid this case with a some effort. I can see a couple of solutions to handle all three cases but they are all a pain to set up and manage. I'm not tied to autofs if another solution is easier and as reliable. All of the systems in the center are running gentoo and are kept up to date. User authentication is also handled through ldap so uid/gid consistency is not an issue. I'd appreciate advice from anyone who has worked though this issue already. Thanks.