DSND - Data Set Delays Report

The DSND report presents information about the utilization (using and delay) of one data set or a group of data sets. For each selected data set, information is given about
  • The volume the data set resides on
  • All jobs that are using this data set or that are waiting for this data set.

RMF sorts the data sets by descending overall delay percentages.

You can use this report as base for further analysis:
  • To investigate the performance of a volume and list all jobs that are delayed because of it, use cursor-sensitive control on any indicator under Volume to display the related DSNV report.
  • To see performance information for a specific job, use cursor-sensitive control on any job listed under Jobname to display the related DSNJ report.
  • To view all data sets which RMF found active in the report interval, or to change the list of data sets to be reported on, enter the command ROPTIONS to display the DSND Report Options panel.

How to request this report

To request the Data Set Delays report, select 3 from the Primary Menu, and then select 3A on the Resource Report Selection Menu (shown in Figure 1). or enter the following command: 
DSND [dsname]

In addition, you can navigate to this report through cursor-sensitive control from the DSNJ report or DSNV report.

Special considerations

The Device Resource Delays report (DEVR) provides USG and DLY values for jobs that are using devices or are waiting for them. This data is gathered in a multistate fashion, this means that there may be several wait records for the same job for the same device. The reporter changes to "pseudo multistate", this can result in one USG counter and one DLY counter in parallel within a cycle, but does not take multiple wait records into account.

Data gathering for the Data Set Delays reports (DSND, DSNJ, and DSNV) is different. Here, several wait records referring to the same device are not treated as being the same and counted only once because they may refer to different data set names, and have to be counted individually.

As a result, the sum of the USG and DLY percentage values in these reports can be different to the USG and DLY percentage values in the DEVR report. Therefore, the three reports contain the headings DUSG% and DDLY% instead of USG% and DLY% to indicate a potential difference to the related values in the DEVR report.

Contents of the report

Figure 1. DSND Report
                      RMF V2R4  Data Set Delays                   Line 1 of 6
Command ===>                                                  Scroll ===> HALF

Samples: 100     System: MVS1  Date: 05/11/19  Time: 10.03.20  Range: 100   Sec

Input Data Set Name: BDA.CTT*

-------------- Data Set Name --------------- Volume  Jobname   ASID DUSG% DDLY%
BDA.CTT.MSPCT.SP41XCTT.CTTGUIDE.BOOK         EDSS99  BOECL2    003C    20    15
                                                     BGGEETEO  0201    15    10
BDA.CTT.MSPCT.SP41XCTT.GUIDE                 EDSS99  BOECL2    003C    13    10
                                                     BGGEETEO  0201    10     8
BDA.CTTX.TEST                                DATA94  BSHR      0022     3    16
BDA.CTT0.INFORM.SEQ                          DATA67  BSHR      0074     3     8

There is no graphic version of this report available.

Field descriptions

Table 1. Fields in the DSND Report
Field Heading Meaning
Input Data Set Name Name of the data set or group of data sets to be reported on.

This is the name which has been specified as command parameter or has been selected via report options.
Data Set Name Name of a data set which was utilized during the report interval and selected for reporting.

RMF lists the data set names by descending overall delay percentages.
Volume Name of the volume on which the data set resides.
Jobname Name of a job using or being delayed by the data set.

RMF lists all jobs for each data set by descending delay percentages.
ASID Hexadecimal address space identifier (ASID) of the job using the data set or waiting for its availability.
DUSG% Percentage of time when the job has had an I/O request accepted by the channel for the volume on which the data set resides, but the request is not yet complete.
Note: See Special considerations.
DDLY% Percentage of time when the job was waiting to use the data set because of contention for the volume where the data set resides.

Report options

The DSND Report Options panel displays a list of all data set names which have been found active during the report interval. You can select a data set name by placing an S in front of the displayed data set name. The selected name is re-displayed in the header field "Selected Data Set Name". This field is an input field which can be used also to enter a data set name or a group of data set names using a "wild card", for example: BDA.CTT*, directly. The wild card example BDA.CTT* lets RMF select all data set names which start with the character sequence BDA.CTT. If someone specifies only "*", RMF reports on all data sets which are being utilized in the report interval.

The current selection is displayed on top of the data set names list.

Figure 2. DSND Report Options Panel
                            RMF DSND Report Options                Line 1 of 12
Command ===>                                                  Scroll ===> HALF

Select (S) or fill-in a data set name or a group of data set names
for the DSND report. To exit press END.

Selected Data Set Name: BDA.CTT*

Sel  Data Set Name
 _   BDA.CTT.MSPCT.SP41XCTT.CTTGUIDE.BOOK
 _   BDA.CTT.MSPCT.SP41XCTT.GUIDE
 _   BDA.CTT0.INFORM.SEQ
 _   BDA.CTTX.TEST
 _   BHEW.ERBMFDTS.LST90514
 _   BSHR.FIX.LINKLIB
 _   RMF.R430.NLS.OLDENG.ERBCOPS3.SEQ
 _   RMF.R430.NLS.OLDENG.ERBFMTS3.SEQ
 _   RMF.R430X10.LPALIB
 _   RMF.R430X10.SRMFCLS
 _   RMF.R430X10.SRMFJPN
 _   RMF.R530.FPFS
Selected Data Set Name
The currently selected name of a data set or group of data sets to be reported on.

This field is an input field and can be overwritten according to the rules for z/OS data set names. It is possible also to use an '*' as "wild card" as last character of the data set name. By using a wild card, all data sets starting with the character sequence before the '*' are reported on no matter which characters follow.

Sel
An S can be placed in front of the data set name to be selected. This results in replacing the data set name in the header field "Selected Data Set Name".
Data Set Name
The name of a data set which was found active during the report interval. The data set names are sorted in alphabetical order.
Note:
  1. The RESET command is not supported.
  2. Only one data set name can be selected.
  3. If a data set name is selected and the data set name in the input field is changed at the same time, the selected data set name is used.
  4. If the data set name is blanked out, it is possible to leave the panel, but the fields in the report will be empty.