On Tue, 2008-04-08 at 07:17 -0700, Ron Hawkins wrote: > The Iceberg's sequential pre-fetch performance was not one of its finest > moments. If you are seeing disconnect time of 10ms or more for your > sequential IO then restricting your work to 8 stripes may not be the best > thing for your workload.
1-3ms seems typical, with the current snapshot showing a max of 4.2. > A larger number of stripes and corresponding BUFNO > changes would increase the IO transfer and cache miss overlap. "Cache miss overlap" -- hadn't thought about that, good catch. I'm leery of striping things indiscriminately; there's a cost involved with allocating additional extents for multivolume datasets. "F CATALOG,REPORT,PERFORMANCE" on my system reports DADSM scratch time of 139ms, which I (without any direct evidence) attribute to SVAA's dynamic space reclaim function. Maybe one of these days I'll turn that off and see if interval space management improves DADSM scratch any. -- David Andrews A. Duda and Sons, Inc. [EMAIL PROTECTED] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
