On Fri, Sep 09, 2005 at 09:43:56AM -0500, Scott Marlowe wrote: > On Wed, 2005-09-07 at 16:15, Jim C. Nasby wrote: > > On Wed, Sep 07, 2005 at 01:02:18PM -0500, Scott Marlowe wrote: > > > On Wed, 2005-09-07 at 12:40, Jim C. Nasby wrote: > > > > On Wed, Sep 07, 2005 at 12:47:43PM -0700, Qingqing Zhuo wrote: > > > > > Xlog will be the only believable data if your system crashed. So it is a dangerous practice to put xlog stuff in RAID0. > > > > > > > > No more or less so than putting your main database on RAID0. If any > > > > drive fails, you lose everything. > > > > > > Sounds like a good place to have replication. > > > > If you used syncronous replication, maybe. Otherwise failure of any > > drive means you just lost data. And remember that the more drives you > > have in your array the more likely you'll have a failure in a given > > time period. > > > > Basically, if you can afford to setup replication on 2 machines with > > RAID0 you can afford to setup RAID10 on one machine, which will usually > > be a better bet. > > Yeah, I was thinking pgpool here. pgpool is a connection pool; it has (almost) nothing to do with replication. It certainly doesn't work to provide any kind of data security on a RAID0 setup. I'm not arguing against anything people have suggested, only pointing out that if you're using RAID0 your data is not safe against a drive failure, except possible using pgcluster (some would argue that statement-based replication isn't as reliable as log-based). -- Jim C. Nasby, Sr. Engineering Consultant jnasby@xxxxxxxxxxxxx Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
