While figuring a way to gather performance data from the scsi disks/ fcp adapters attached to Linux images running under z/VM, I gave ziomon, a feature delivered with the s390-tools package, a try before I could propose the use of such tool to my customers. This tool allows, besides other neat things, the customer to create utilization and traffic reports for the FCP adapters and SCSI disks attached to their systems through the use of blktrace.
BLKTRACE requires CONFIG_BLK_DEV_IO_TRACE to be enabled at the kernel, a requirement that seems to be satisfied on SLES10 images, but for some reason not on SLES 11 SP1 servers, whose latest default GA kernel I checked (2.6.32.36-0.5-default ) was delivered without this option, which, pretty much , removes ziomon from the system admin tool set. I later learned that Suse has decided to split the kernel in different packages , and in order to use the version with these tracing options enabled I would need to boot with the kernel-trace version, which, according to the release notes for SLES11 SP1 ( http://www.novell.com/linux/releasenotes/s390x/SUSE-SLES/11-SP1/) is a supported version. If I need to collect this info on a more permanent basis I would need to make this version of the kernel ( kernel-trace) my standard option in zipl.conf. But before I do that , I'd appreciate if you could share your thoughts on the penalties I'd suffer from both a performance and resource allocation perspectives for running this "tracing enabled" kernel in production. Thanks ... Ricardo ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
