On Thu, Jul 22, 2004 at 09:53:45AM -0500, Michael Conrad Tadpol Tilstra wrote: > On Thu, Jul 22, 2004 at 12:53:48PM +0300, Levent Serinol wrote: > > Hi, > > I have done some benchmark tests with postmark(tests repeated many > > times). There is one client (also it is lock server). and another one > > which exports it's scsi hard disk with gnbd. > [snipped a lot of nice data] > > as you can see nolock results is 2 times (some parts 3 times) faster > > then with locked one . > > what could be the problem ? is there any workaround or settune option > > (releasing locks earlier,etc...) ? > > the biggest thing you are probably running into is that when running > with lock_nolock, gfs knows that it is not in a cluster, therefor it can > enable some optimisations that only work for lcoal filesystems. These > optimisations would corrupt disk data if you had multiple nodes mounted. You can turn off those optimizations with lock_nolock by mounting with "-o ignore_local_fs". That will let us figure out what is optimizations and what is lock latency. > There is also no network traffic for handling lock in lock_nolock, but > that is minor compaired to the local file system optimisations. > > Basically, gfs with lock_nolock should always be quite faster than with > any cluster locking (lock_gulm or lock_dlm). > > Ken could say more on this. > > -- > Michael Conrad Tadpol Tilstra > Reality is for people who lack imagination. > -- > > Linux-cluster@xxxxxxxxxx > http://www.redhat.com/mailman/listinfo/linux-cluster -- Ken Preslan <kpreslan@xxxxxxxxxx>
