AFAIK, vim fsyncs, azureus fsyncs, and may be many other applications
fsyncs but not only databases.
Definitly turn off fsync() is a bad idea. I just wonder how bad r4's
fsync() performance is.
It seems the result is: disabled fsync() r4 is even slower than
enabled fsync() ext3.o
Is it never be possible to improve that? I found in the mailing-list
that Hans talked it for many years. this must be a CRITICAL
performance flaw for r4.
2007/1/25, [EMAIL PROTECTED] [EMAIL PROTECTED]:
On Wed, 24 Jan 2007 22:05:53 +0800, Xu CanHao said:
extremely low performance, i managed to turn off fsync() in
fs/reiser4/plugin/file/file.c (nullify the sync_unix_file() function),
(Maybe you understand the following, if so, feel free to ignore. I'm
mostly making sure the list archives have this note so anybody else tempted
to do this will think twice)...
Note that this can be *very* dangerous to the health of your database
if you implement it blindly without understanding the *full* implications.
Basically, applications almost never call fsync() unless they need it for
database consistency. A system crash at an inopportune time *will* totally
ruin your database.
