On 9/19/07, Carlos Moreno <moreno_pg@xxxxxxxxxxx> wrote: > Hi, > > Anyone has tried a setup combining tablespaces with NFS-mounted partitions? > > I'm considering the idea as a performance-booster --- our problem is > that we are > renting our dedicated server from a hoster that does not offer much > flexibility > in terms of custom hardware configuration; so, the *ideal* alternative > to load > the machine with 4 or 6 hard drives and use tablespaces is off the table > (no pun > intended). > > We could, however, set up a few additional servers where we could configure > NFS shares, mount them on the main PostgreSQL server, and configure > tablespaces to "load balance" the access to disk. > > Would you estimate that this will indeed boost performance?? (our system > does lots of writing to DB --- in all forms: inserts, updates, and deletes) > > As a corollary question: what about the WALs and tablespaces?? Are the > WALs "distributed" when we setup a tablespace and create tables in it? > (that is, are the WALs corresponding to the tables in a tablespace stored > in the directory corresponding to the tablespace? Or is it only the > data, and > the WAL keeps being the one and only?) > > Thanks, > > Carlos About 5 months ago, I did an experiment serving tablespaces out of AFS, another shared file system. You can read my full post at http://archives.postgresql.org/pgsql-admin/2007-04/msg00188.php On the whole, you're not going to see a performance improvement running tablespaces on NFS (unless the disk system on the NFS server is a lot faster) since you have to go through the network as well as NFS, both of which add overhead. Usually, locking mechanisms on shared file systems don't play nice with databases. You're better off using something else to load balance or replicate data. Peter P.S. Why not just set up those servers you're planning on using as NFS shares as your postgres server(s)? ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
