Careful with those numbers. Some of those tests were on some pretty old hardware. There have been z/VM SCSI performance improvements, qioassist, and 2 rounds of FCP firmware improvements in the meantime. More up to date info is probably there. You'll just have to click through some of the links.
Also, this might help: http://public.dhe.ibm.com/common/ssi/ecm/en/zsw03129usen/ZSW03129USEN.PDF Ray Higgs System z FCP Development Bld. 706, B24 2455 South Road Poughkeepsie, NY 12601 (845) 435-8666, T/L 295-8666 rayhi...@us.ibm.com Linux on 390 Port <LINUX-390@vm.marist.edu> wrote on 03/11/2011 01:00:48 PM: > Christian Paro <christian.p...@gmail.com> > Sent by: Linux on 390 Port <LINUX-390@vm.marist.edu> > > 03/11/2011 01:00 PM > > Please respond to > Linux on 390 Port <LINUX-390@vm.marist.edu> > > To > > LINUX-390@vm.marist.edu > > cc > > Subject > > Re: FBA/SCSI vs ECKD zLinux on VM > > A full set of benchmarks for different disk technologies with z/VM: > > http://www.vm.ibm.com/perf/reports/zvm/html/520dasd.html > > On Fri, Mar 11, 2011 at 12:57 PM, Donald Russell <russell....@gmail.com>wrote: > > > I currently have a dozen or so RHEL 5.6 zLinux running on multiple VM 6.1 > > (well, 5, but 6.1 RSN), on z10 processors. > > > > The largest (disk space) is about 3TB and is currently FBA/SCSI.... > > > > We're thinking of changing this to ECKD to take advantage of the SAP to do > > the real IO, instead of IO being handled within zLinux itself. > > > > (We have other zLinux system using ECKD) > > > > On one hand using ECKD will get us some CPU cycles back due to more work > > being done by the SAP, but just recenly I heard that IO can be faster > > (higher throughput) with FBA/SCSI. > > > > I'm assuming there's no clear answer as to which is best, because like so > > many performance tuning things, the answer is always "it depends". > > > > But, what are other people doing? My experience so far seems to be that the > > choice of SCSI or ECKD depends on the background of the people making the > > decision.... people with a s390 background are familiar with ECKD, people > > coming from a unix/linux background are familiar with SCSI.. > > > > Thank you > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > > visit > > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > ---------------------------------------------------------------------- > > For more information on Linux on System z, visit > > http://wiki.linuxvm.org/ > > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
