On Mon, 2007-10-01 at 10:13 -0700, Josh Berkus wrote: > > Maybe we need to actively discourage people from running Postgres > > against NFS-mounted data directories. Shane Kerr's paper cited above > > mentions some other rather scary properties, including O_EXCL file > > creation not really working properly. > > Wouldn't you be describing a Linux-specific issue, though? And possibly > kernel-specific?
Possibly, though if you have any specific refutations of the Kerr paper then it would be a good idea to air them. It isn't enough to just hint some exist. > It's hard to reconcile this with the real-world performance of > PostgreSQL on NFS, which is happening all over the place. Most notably, > Joe Conway's 20,000 txn/sec. > > I *do* think it's an accurate statement that if you're going to use > Postgres, or any other OLTP database, on NFS you'd better have access to > a NAS expert. But to say that it's a bad idea even if you have expert > help is probably going to far. I can see many papers on database performance on NFS, but I don't see any discussion of potential reliability concerns. If anybody sits near an NAS expert, it would be great to have that discussion. I have found some comments that other databases require "specific configuration settings to ensure efficient and correct usage" of NFS "to access NAS storage devices". -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
