Alas, there is no command to determine what application is consuming disk reads/writes within UV. There are OS commands that show what CPU usage is for an individual user. Sometimes there is a correlation between CPU usage and the amount of disk requests coming from the application. I am unaware of any OS command that shows the disk usage by each user. There may be a command, but I am not aware of it.
I concur with what Rodney Baakkonen stated. If you don't have enough disk drives to service all of the reads and writes, then you just plain have to add more disk drives. But, another alternative is to add Memory to the main system. By retaining more disk segments in memory, you will reduce the TOTAL number of disk READs requested from the host system - which is a very good thing. Another interesting benefit is that the heavily used disk segments get "hiked higher" in memory and are not paged out. In other words, the more a disk segment is used, the less likely it will have to be read again. In all Operating Systems, any left over memory is used for disk caching. The order of memory usage is: 1) Operating System 2) UDT or UV requirements 3) Variable space used by users 4) any memory left unused will be used for Disk Caching (note: some OS configurables may have to be changed for it to recognize all of the memory). Another benefit of more memory is a reduction in time to process all SELECT or LIST statements! The more memory available, the faster the sorting function will complete. So, you may wish to max out the memory in your system first before adding disk given the dual benefit of faster sorts and less disk reads coming from the host system. A related topic is to STRIPE your data across disk drives. This will allow many disk drives to be active against the same file. Striping also leads to the question of the RAID configuration. RAID 10 (Striping and Mirroring) is best, but requires more disk drives. RAID 5 is the slowest and "may" cause problems on systems where they are right on the edge of having enough disk drives. I won't dive into it here, but just remember that the RAID configuration can have a HUGE impact. Respectfully Submitted, Steve Stephen M. O'Neal, CDP & IBM U2 Certified Services Sales Specialist North America U2 Lab Services Information Management, IBM Software Group ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/
