>>> "Joshua D. Drake" <[EMAIL PROTECTED]> wrote: > On Thu, 2008-11-06 at 13:02 -0600, Kevin Grittner wrote: >> the new kernel >> defaulted to using write barriers, while the old kernel didn't. Since >> we have a BBU RAID controller, we will add nobarrier to the fstab >> entries. This makes file creation and unlink each about 20 times >> faster. > > Woah... which version of the kernel was old and new? old: [EMAIL PROTECTED]:/var/pgsql/data/test> cat /proc/version Linux version 2.6.5-7.287.3-bigsmp ([EMAIL PROTECTED]) (gcc version 3.3.3 (SuSE Linux)) #1 SMP Tue Oct 2 07:31:36 UTC 2007 [EMAIL PROTECTED]:/var/pgsql/data/test> uname -a Linux DBUTL-PG 2.6.5-7.287.3-bigsmp #1 SMP Tue Oct 2 07:31:36 UTC 2007 i686 i686 i386 GNU/Linux [EMAIL PROTECTED]:/var/pgsql/data/test> cat /etc/SuSE-release SUSE LINUX Enterprise Server 9 (i586) VERSION = 9 PATCHLEVEL = 3 new: [EMAIL PROTECTED]:~> cat /proc/version Linux version 2.6.16.60-0.27-smp ([EMAIL PROTECTED]) (gcc version 4.1.2 20070115 (SUSE Linux)) #1 SMP Mon Jul 28 12:55:32 UTC 2008 [EMAIL PROTECTED]:~> uname -a Linux SAWYER-PG 2.6.16.60-0.27-smp #1 SMP Mon Jul 28 12:55:32 UTC 2008 x86_64 x86_64 x86_64 GNU/Linux [EMAIL PROTECTED]:~> cat /etc/SuSE-release SUSE Linux Enterprise Server 10 (x86_64) VERSION = 10 PATCHLEVEL = 2 To be clear, file create and unlink speeds are almost the same between the two kernels without write barriers; the difference is that they were in effect by default in the newer kernel. -Kevin
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