I presume you are using the devr report... See Pending, disconnect and other gobbledegook. <https://colinpaice.blog/2020/11/18/pending-disconnect-and-other-gobbledegook/> for some info on what the IO wait times mean.
It might be Disconnect – Time spent accessing the disks. This could be accessing local disks, or accessing remote (mirrored) disks. The Storage controller is not doing any work while the disk is busy. - The volume is reserved by another system. - Waiting for the arm to move, or the disk to rotate (for spinning disks). - The disk is processing the request – for example a cache miss means the disk has to be read. - Waiting for a signal from a remote peer to say that write data has been stored. - Some SMF records have a field “Read Disconnect time”. This indicates the read wanted a record which was not in the controller cache. You can collect SMF42-6 records - IO stats at the dataset level. I have a program which prints out these stats. The RMF data you see is also in the SMF 79-9 records. Colin On Thu, 3 Aug 2023 at 08:21, Jason Cai <[email protected]> wrote: > Dear all, > > I have a question about the RMF III Device Resource Delay report > > I noticed that the DLY% value of one disk is 100 every 6 minutes. This > disk has HyperPAV enabled. > > ACT RATE = 5.1,RESP TIME=200 ACT%=2 CON%=1 DSC%=1 USG%=0 DLY%=100 > > > According to the IBM manual, DLY% means "Percentage of time when the > job was waiting to use the data set because of contention for the volume > were the data set resides". > > I would like to know how to identify the cause of this contention. What > command should I use? Do I need to enable GRS MONITOR? > > Any suggestions would be greatly appreciated! > > Thank you for your attention and assistance. > > Sincerely, > > Jason Cai > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
