[OpenAFS-devel] fsync/nofsync performance numbers on Solaris

[Robert Banz]

I know this isn't a super-scientific test, but, I wanted to get an  
idea of what sort of write performance changes you see on Solaris  
with different filesystems, using, or not using fsync()'ing all over  
the fileserver...

Test System: Dell 2650, 8G ram, local SCSI disk
OS: Solaris 10u2 x86 (32bit mode...ugh)

AFS: OpenAFS 1.4.1 (both client & server), namei fileserver

Cache: 2G RAM cache (lofi'd ufs filesystem cache)

Test: Very simple.  Untar gcc-4.1.1 into a virgin volume, on a virgin  
fs, rebooting
		    between test to clear the memory cache...

backing store           fsync'ing       no-fsync'ing
---------------------------------------------------------
logging ufs              8min54sec	2min36sec
zfs			  n/a		1min46sec
zfs w/compression 	  n/a		1min59sec

I didn't bother testing zfs with the fsync() on, I knew it would be  
pretty horrible in light of the current fsync "bug" it's got...

Yes, that really is a 4x performance boost on writes.  w00t, as the  
kids say...

-rob