That's somewhat outdated information at least for SLES 9 & 10. We have Linux I/O statistics for FCP/SCSI and shortly we'll have FCP adapter I/O statistics, too.
It is true that ECKD attached disks provide QoS features like end-to-end data protection and is the dominant I/O attachment for Linux. It is also true that customers would usually observe higher throughput with FCP attached storage. More performance related data to disk I/O is available at http://www-128.ibm.com/developerworks/linux/linux390/perf/index.html and more specific information for related to the DS8000 at http://www-128.ibm.com/developerworks/linux/linux390/perf/tuning_res_dasd_ds8000.html Best regards Ingo Linux on 390 Port <[email protected]> wrote on 26.03.2007 22:38:21: > When performance is bad, do you want to know why? Until we know how > to show when the SAN > is impacting your application and how - do you want to trust your > production to something > where performance is not manageable? > For example, an ibm controller was benchmarked first as eckd, then > as scsi. on eckd, we > get cache stats - could show the dasd fast write filled up, and > could show response time. > for scsi, all we could show was thruput was degraded. we can't > even measure silly > response time numbers on scsi. > > > Lionel B. Dyck wrote: > > > I've heard several good reasons to have my zlinux images use dasd that is > > on the fibre connected san and a few for using the old tried and true > > dasd. What I'd like to find out is what is true and what isn't - basically > > what is considered the best practice for zlinux dasd. > > > > Thus - what do y'all think? > > > > Thanks in advance. > > > > Lionel B. Dyck, Consultant/Specialist zLinux Platform > > Client and Platform Engineering Services (CAPES) > > KP-IT Enterprise Engineering, Manager Toni Nicotera > > 925-926-5332 (8-473-5332) | E-Mail: [EMAIL PROTECTED] > > AIM: lbdyck | Yahoo IM: lbdyck > > Kaiser Service Credo: "Our cause is health. Our passion is service. We’re > > here to make lives better.” > > > > “Never attribute to malice what can be caused by miscommunication.” > > > > NOTICE TO RECIPIENT: If you are not the intended recipient of this e-mail, > > you are prohibited from sharing, copying, or otherwise using or disclosing > > its contents. If you have received this e-mail in error, please notify the > > sender immediately by reply e-mail and permanently delete this e-mail and > > any attachments without reading, forwarding or saving them. Thank you. > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > [attachment "barton.vcf" deleted by Ingo Adlung/Germany/IBM]
