We're considering purchasing filer(s) as part of a mail system upgrade. Setup would be a cluster of redundant and very similarly configured machine around one or more filers containing all the real data (/var/spool/mail for customers, some web serving, and other stuff). Most likely all the clustered machines will do delivery to the shared area and POP/IMAP reading.
Our desired platform is PCs running FreeBSD (or perhaps BSDI). One major problem is that none of the PC Unix environments (FreeBSD, BSDI, Linux) have working NFS file locking. We could implement some hacks using file based locking, but I'm worried about the hassle and performance issues here.
In fact, even with working NFS locking, I'd be worried about sharing mail spools in this fashion.
I've also had advice from people who recommend avoiding NFS entirely and going for transparent proxies and multiple machines for scalability. But that leaves a reliability/redundancy issue (hardware RAIDs, s/w mirroring, ...).
What I'm wondering and perhaps people on the list can help is: - anyone doing something similar in an ISP environment (what platform, what filer, how many users?) - any advice/ideas on the locking issue - will filers perform well in this environment? some of the client applications are not well behaved and do things like copy the entire mail box; local disk would obviously be faster (I can get over 35MB/sec using multiple local disks on PCs), but I'm not sure it's that big an issue -- Alan Judge Phone: +353-1-6046901 Indigo Network Operations Centre Fax: +353-1-6046948