Обсуждение: VX_CONCURRENT flag on vxfs( 5.1 or later) for performance for postgresql?

Dear all

When database files are on a VxFS filesystem, performance can be
significantly improved by setting the VX_CONCURRENT cache advisory on
the file according to vxfs document,

my question is that have any tested by this?


#include <sys/fs/vx_ioctl.h>
ioctl(fd, VX_SETCACHE, VX_CONCURRENT);


Regards

HSIEN WEN

HSIEN-WEN CHU <hsienwen.chu@googlemail.com> writes:
> When database files are on a VxFS filesystem, performance can be
> significantly improved by setting the VX_CONCURRENT cache advisory on
> the file according to vxfs document,

Presumably, if whatever behavior this invokes were an unalloyed good,
they'd have just made it the default.  The existence of a flag makes
me suppose that there are some clear application-visible downsides.
What are they?

BTW, please do not cross-post the same question to three different lists.
        regards, tom lane