Bryan Keller wrote:
It sounds like NFS is a viable solution nowadays. I a still going to shoot for using iSCSI, given it is a block-level protocol rather than file-level, it seems to me it would be better suited to database I/O.
Please digest carefully where Joe Conway pointed out that it took them major kernel-level work to get NFS working reliably on Linux. On anything but Solaris, I consider NFS a major risk still; nothing has improved "nowadays" relative to when people used to report regular database corruption running it on other operating systems. Make sure you read http://www.time-travellers.org/shane/papers/NFS_considered_harmful.html and mull over the warnings in there before you assume it will work, too.
I don't think I've ever heard from someone happy with an iSCSI deployment, either. The only way you could make an NFS+iSCSI storage solution worse is to also use RAID5 on the NAS.
I'd suggest taking a look at http://wiki.postgresql.org/wiki/Shared_Storage and consider how you're going to handle fencing issues as well here. One of the reasons SANs tend to be preferred in this area is because fencing at the fiber-channel switch level is pretty straightforward. DAS running over fiber-channel can offer the same basic features though, it's just not as common to use a switch in that environment.
-- Greg Smith 2ndQuadrant US greg@xxxxxxxxxxxxxxx Baltimore, MD PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us "PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
