Ron Mayer wrote: > Bruce Momjian wrote: > > Greg Smith wrote: > >> Bruce Momjian wrote: > >>> I thought our only problem was testing the I/O subsystem --- I never > >>> suspected the file system might lie too. That email indicates that a > >>> large percentage of our install base is running on unreliable file > >>> systems --- why have I not heard about this before? > >>> > >> he reason why it > >> doesn't bite more people is that most Linux systems don't turn on write > >> barrier support by default, and there's a number of situations that can > >> disable barriers even if you did try to enable them. It's still pretty > >> unusual to have a working system with barriers turned on nowadays; I > >> really doubt it's "a large percentage of our install base". > > > > Ah, so it is only when write barriers are enabled, and they are not > > enabled by default --- OK, that makes sense. > > The test program I linked up-thread shows that fsync does nothing > unless the inode's touched on an out-of-the-box Ubuntu 9.10 using > ext3 on a straight from Dell system. > > Surely that's a common config, no? Yea, this certainly suggests that the problem is wide-spread. -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
