allen%qal.Berkeley.EDU@ucbvax.berkeley.edu (Allen Sonafrank) (06/15/89)
We have a network of 66 Sun 3/50 workstations, mostly diskless, supported by five Sun fileservers (3/160, 3/160, 3/180, 3/280, 4/280). Each server has a single Xylogics 450 or 451 disk controller, with two disk drives. We are currently running SunOS 3.5 on all but the SPARC server and four workstations, and are reluctant to upgrade :-) to SunOS 4.0 with our 4mb workstations. We are attempting to overcome a serious I/O bottleneck on the servers. They can't satisfactorily handle the demands placed on them by NFS service and workstation paging at times of peak load. Anecdotal evidence leads us to believe that we could solve this problem by adding additional disk controllers, so that each disk drive was served by a single controller. Does anyone have experience which compares machines with two controllers to machines with a single controller? What kind of increase in I/O throughput did you notice after doubling up on Xylogics 450 or 451 (SMD) disk controllers in a server? Has anyone possibly doubled up on 450/451 controllers, and then later upgraded to a single Xylogics 7053 (SMD-4) disk controller and OS 4.0? The increase in throughput is said to be up to 100% over a single 450 or 451. So such a system should still run faster than one with the old SMD controllers doubled. We're thinking that the speed of the Xylogics 7053 might compensate for the increased paging we would expect under SunOS 4. What has your experience been? Please reply by email, and I'll summarize. Thanks much. +------------------------------------------------------------------------+ | Allen Sonafrank | | | System & Network Manager | allen@qal.berkeley.edu | | QAL, 2220 Piedmont Ave. | ucbvax!qal!allen | | University of California | allen@ucbqal.bitnet | | Berkeley, CA 94720 | | | (415) 642-9890 | | +------------------------------------------------------------------------+