Bruce Momjian [EMAIL PROTECTED] wrote:
Yes, this double-writing is a problem. Suppose you have your WAL on a
separate drive. You can fsync() WAL with zero head movement. With a
log based file system, you need two head movements, so you have gone
from zero movements to two.
It may be
I got some information from Stephen Tweedie on this - please keep him
Cc: as he's not on this list
Bruce Momjian [EMAIL PROTECTED] writes:
I was talking to a Linux user yesterday, and he said that performance
using the
Hi,
On Fri, May 04, 2001 at 01:49:54PM -0400, Bruce Momjian wrote:
Performance doing what? XFS has known performance problems doing
unlinks and truncates, but not synchronous IO. The user should be
using fdatasync() for databases, btw, not fsync().
This is hugely helpful.
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I got some information from Stephen Tweedie on this - please keep him
Cc: as he's not on this list
Bruce Momjian [EMAIL PROTECTED] writes:
I was talking to a Linux
I was talking to a Linux user yesterday, and he said that performance
using the xfs file system is pretty bad. He believes it has to do with
the fact that fsync() on log-based file systems requires more writes.
With a standard BSD/ext2 file system, WAL writes can stay on the same
cylinder to
The problem with log based filesystems is that they most likely
do not know the consequences of a write so an fsync on a file may
require double writing to both the log and the real portion of
the disk. They can also exhibit the problem that an fsync may
cause all pending writes to require
* Bruce Momjian [EMAIL PROTECTED] [010502 14:01] wrote:
I was talking to a Linux user yesterday, and he said that performance
using the xfs file system is pretty bad. He believes it has to do with
the fact that fsync() on log-based file systems requires more writes.
With a standard
* Bruce Momjian [EMAIL PROTECTED] [010502 15:20] wrote:
The problem with log based filesystems is that they most likely
do not know the consequences of a write so an fsync on a file may
require double writing to both the log and the real portion of
the disk. They can also exhibit the
