I haven't tried gfs yet, but did you simply test simultaneous access to the same local disk (without gfs) by 2 separate processes: generally peformance drops because of disk seek time (the reason is mechanical) Disks always have much lower performance when shared between 2 processes on the same machine or 2 processes on separate machines (it is the same as having a dual cpu) This is just an idea... not very sure if this is your problem. Jure Pečar wrote: >Hi all, > >Since I've got no reply on redhat cluster list, I'm trying here ... > >I'm testing a rhcs4 cluster with gfs. I noticed some poor performance while >tarring data from a gfs volume to a local disk from both nodes at the same >time, so I deceided to have a closer look. > >Here are the bonnie++ results: http://jure.pecar.org/gfs/ > >I don't know what to think of these ... but I doubt it's normal for >performance to go down by an order of magnitude when both nodes are doing >some i/o to the shared file system ... > >I'd like to see some numbers from other gfs systems to see if this is >normal and if it is not, how to figure out what's wrong and how to fix it. > >Thanks, > > > >