---
title: "SMF 78-3 I/O Queuing Activity"
slug: "smf-78-3-io-queuing-activity"
updated: 2024-02-29T09:15:08Z
published: 2024-02-29T09:15:08Z
canonical: "docs.zetaly.io/smf-78-3-io-queuing-activity"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zetaly.io/llms.txt
> Use this file to discover all available pages before exploring further.

# SMF 78-3 I/O Queuing Activity

## Introduction

Reports I/O queuing activity and HyperPAV and SuperPAV activity. It contains an entry for each logical control unit that had any activity during the interval.

## Fields

### Stored in pavData

| SMF Field | DB Column name | Description | Unit |
| --- | --- | --- | --- |
|  | recType | Value is always 0 |  |
| SMF78DAT | startTime | Date when the RMF measurement interval started |  |
| SMF78DTE/TME | endTime | Date when the record was moved into the SMF buffer |  |
| SMF78INT | seconds | Duration of the RMF measurement interval | second |
| SMF78SID | sid | System identification |  |
| SMF78XNM | sysplex | Sysplex name as defined in parmlib member COUPLExx |  |
| SMF78SNM | systemName | System name for current system as defined in parmlib member IEASYSxx SYSNAME parameter |  |
| R783ID2 | lcu | Logical control unit identifier |  |
| R783CSS | cssid | Channel Subsystem ID |  |
| R783CU1 | cunum | First control unit attached |  |
| R783DST | lcuFlags | Data Status |  |
| R783GFLG | globalFlags | IOQ global flags |  |
| R783CFL | cfgFlags | Configuration change flags |  |
| SMF78SAM | sampleCount | Number of RMF samples |  |
| R783QSM | accQueueLen | Sum of total length of the CU-HDR queue |  |
| R783QCT | queueLength | Number of entries on the CU-HDR queue |  |
| R783HAIU | maxAlias | The high water mark of the number of in-use HyperPAV-alias devices for the LSS |  |
| R783HCAD | maxBaseUse | The high water mark of the number of aliases concurrently in use by one of the HyperPAV-base devices of the LSS |  |
| R783HIOQ | maxQueued | The high water mark of queued I/O requests |  |
| R783MCMN | minChannel | Minimum number of DCM managed channels used |  |
| R783MCMX | maxChannel | Maximum number of DCM managed channels used |  |
| R783MCDF | defChannel | Defined number of DCM managed channels |  |
| R783PTM | pathTaken | Accumulated path taken count for DCM managed channels |  |
| R783DPBM | portBusy | Accumulated director port busy count for DCM managed channels |  |
| R783CUBM | cuBusy | Accumulated control unit busy count for DCM managed channels |  |
| R783SBSM | switchBusy | Switch busy count summation for DCM-managed channels |  |
| R783HNAI | pavMisses | The number of times an I/O could not start because no HyperPAV-aliases were available |  |
| R783HTIO | pavIo | The total number of HyperPAV I/O requests for the LSS |  |
| R783DCTM | connTime | Accumulated device connect time | 128 microseconds |
| R783DDTM | discTime | Accumulated device disconnect time | 128 microseconds |
| R783CBTM | dcBusyTime | Accumulated delay time for DCM-managed channels because of a busy control unit |  |
| R783CMRM | dcCmrTime | Accumulated initial command response time for DCM-managed channels |  |
| R783CSST | cssTime | Channel subsystem wait time | 128 microseconds |
| R783DST | isPav |  |  |
| R783DST | isDcm |  |  |
|  | actionId |  |  |

### Stored in lcuData

| SMF Field | DB Column name | Description | Unit |
| --- | --- | --- | --- |
|  | recType | Value is always 0 |  |
| SMF78DAT | startTime | Date when the RMF measurement interval started |  |
| SMF78DTE/TME | endTime | Date when the record was moved into the SMF buffer |  |
| SMF78INT | seconds | Duration of the RMF measurement interval | second |
| SMF78SID | sid | System identification |  |
| SMF78XNM | sysplex | Sysplex name as defined in parmlib member COUPLExx |  |
| SMF78SNM | systemName | System name for current system as defined in parmlib member IEASYSxx SYSNAME parameter |  |
| R783ID2 | lcu | Logical control unit identifier |  |
| R783CPID | chpid | Channel path identifier |  |
| R783CSS | cssid | Channel Subsystem ID |  |
| R783CU1 | cunum | First control unit attached |  |
| R783CFL | chpFlags | Configuration change flags |  |
| R783CPAT | pathFlags | Path attributes |  |
| SMF78SAM | sampleCount | Number of RMF samples |  |
| R783PT | takeCount | Number of times channel path was taken |  |
| R783CBTM | busyTime | Accumulated delay time for DCM-managed channels because of a busy control unit | second |
| R783CMRM | cmrTime | Accumulated initial command response time for DCM-managed channels | second |
|  | actionId |  |  |