CACHSUM - Cache Summary Report

The Cache Summary report (CACHSUM) provides an overview about the activities in the cache subsystem for all SSIDs. You might take this as starting point when analyzing I/O performance to get a first impression about the I/O processing.

If you feel that further analysis is required, you may continue with the Cache Detail report (see CACHDET - Cache Detail Report).

How to request this report

To request the CACHSUM report, select S on the Primary Menu, and then select 8 on the Sysplex Report menu (shown in Figure 1), or enter the following command: 
CACHSUM

Contents of the report

Figure 1. CACHSUM Report
                      RMF V2R4   Cache Summary    - SYSDPLEX       Line 1 of 23
                                                                               
 Samples: 60      Systems: 3    Date: 05/11/19  Time: 13.35.00  Range: 60    Sec
                               CDate: 05/11/19 CTime: 13.34.57 CRange: 59    Sec
                                                                               
 SSID  CUID  Type-Mod  Size   I/O    Hit   Hit   -- Miss ---  Read  Seq  Async 
                              Rate    %    Rate  Total Stage    %   Rate Rate  
                                                                               
 2180  2182  2107-951  124G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 4000  405C  2107-981  246G   23.8   100   23.8    0.0   0.0   100   0.0   0.0 
 4100  4102  2107-981  246G  208.6   100  208.6    0.0   0.0  99.8   0.0   0.0 
 4300  43AC  2107-981  246G   13.7   100   13.7    0.0   0.0   100   0.0   0.0 
 4400  44C1  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 4500  45C3  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 4600  46C4  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 4700  47BF  2107-981  246G    6.8  99.5    6.8    0.0   0.0  27.5   0.0   0.0 
 4800  48C2  2107-981  246G   47.8   100   47.8    0.0   0.0  94.3   0.0   0.0 
 4A00  4A27  2107-981  246G    5.5   100    5.5    0.0   0.0  56.4   0.0   0.0 
 4D00  4D05  2107-981  246G    5.3   100    5.3    0.0   0.0  53.7   0.2   0.5 
 5000  5040  2107-981  246G    0.3   100    0.3    0.0   0.0   100   0.0   0.0 
 5100  51A8  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 5300  53AB  2107-981  246G    5.1   100    5.1    0.0   0.0  52.5   0.0   0.0 
 5400  5402  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 5800  58BF  2107-981  246G   13.9   100   13.9    0.0   0.0  86.1   0.0   0.0 
 5A00  5AA9  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 5B00  5B70  2107-981  246G   38.4   100   38.4    0.0   0.0  49.3   0.0   0.0 
 5C00  5C04  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 5D00  5D5F  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 5F00  5F02  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 D600  D611  2107-951  124G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0 
 D680  D6D2  2107-951  124G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0

There is no graphic version of this report available.

If you place the cursor on any field of the first three columns, a pop-up window appears showing details for the selected SSID. Cursor-sensitive control of the other columns leads you to the CACHDET report. Start of change
Figure 2. CACHSUM Report - SSID Details
                     RMF V2R4   Cache Summary    - SYSPLEX        Line 1 of 23 
                                                                               
Samples: 60      Systems: 3    Date: 05/11/19  Time: 13.35.00  Range: 60    Sec
                              CDate: 05/11/19 CTime: 13.34.57 CRange: 59    Sec
SSI ---------------------------------------------------------------------------
    |                        RMF Cache SSID Information                       |
    |                                                                         |
218 | The following details are available for SSID 4100                       |
400 | Press Enter to return to the Report panel.                              |
410 |                                                                         |
430 | CUID    : 4102     Config:  246G             NVS   : Active             |
440 | Type-Mod: 2107-981 Avail :  211G             Config:   16G              |
450 |                    Offl  :     0             Pinned:     0              |
460 |                    Pinned:     0                                        |
470 |                                                                         |
480 |        ------ Read ------   --------- Write ---------   Read   Tracks   |
4A0 |         Rate    Hit  Hit%    Rate   Fast    Hit  Hit%     %             |
4D0 | Norm   197.5  197.5   100     0.4    0.4    0.4   100   99.8      0.0   |
500 | Seq     10.7   10.7   100     0.0    0.0    0.0   100   99.8      0.0   |
510 | CFW      0.0    0.0   0.0     0.0    0.0    0.0   0.0    0.0            |
530 | Total  208.2  208.2   100     0.4    0.4    0.4   100   99.8            |
540 |                                                                         |
580 |                                                                         |
5A0 |                                                                         |
5B0 |                                                                         |
5C0 ---------------------------------------------------------------------------

5D00  5D5F  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0  
5F00  5F02  2107-981  246G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0  
D600  D611  2107-951  124G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0  
D680  D6D2  2107-951  124G    0.0   0.0    0.0    0.0   0.0   0.0   0.0   0.0
End of change

Field description

Table 1. Fields in the CACHSUM Report
Field Heading Meaning
Device reserve activity can cause a data gatherer interface to wait until a RESERVE has been released. This in turn can cause the cache interval to be much longer than a regular RMF interval.

Therefore, CDate, CTime and CRange are used to show the actual point in time to which the cache interval start is related, and the actual cache interval length. All rates shown in the report are based on CRange, not on Range.

Note: The reported storage capacities for cache and non-volatile storage (NVS) represents only the Cluster Processor Complex in the storage server, that controls the subsystem. Since a typical storage server has two clusters, you must double the reported capacities to get the actual sizes.
CDate Date on which the cache interval started.
CTime Time at which the cache interval started.
CRange Cache interval time.
SSID Subsystem identifier: a number assigned during the installation of the subsystem that uniquely identifies the storage subsystem.
CUID Physical control unit number of the caching subsystem. This is equal to the lowest device number, or the device that has been turned online first, respectively.
Type-Mod Hardware type and model.
Size Amount of physical storage that is configured in this storage subsystem (in giga- or megabytes).
I/O Rate Rate of I/O requests.
Hit % Percentage of I/Os that where processed within the cache (cache hits) based on the total number of I/Os.
Hit Rate I/O rate of all cache hits. This is the sum of:
READ
Rate of SEARCH/READ requests that completed without accessing the DASD
DFW
Rate of DASD FAST WRITE requests
CFW
Rate of WRITE and READ-AFTER-WRITE requests that are processed in cache
Miss Total I/O rate of all requests that accessed DASD.

This is the sum of Stage rates (see below) and other request rates (inhibit cache load, BYPASS, CFW BYPASS, DFW INHIBIT).
Miss Stage Rate of normal or sequential I/O requests that accessed DASD.
Read % Percentage of READ requests based on all READ and WRITE requests.
Seq Rate Rate of tracks that have been staged due to cache misses for sequential I/O requests.
Async Rate Rate of tracks that have been destaged asynchronously.
Table 2. Fields in the CACHSUM Report - SSID Details
Field Heading Meaning
Note: The reported storage capacities for cache and non-volatile storage (NVS) represents only the Cluster Processor Complex in the storage server, that controls the subsystem. Since a typical storage server has two clusters, you must double the reported capacities to get the actual sizes.
CUID Physical control unit number of the caching subsystem. This is equal to the lowest device number, or the device that has been turned online first, respectively.
Type-Mod Hardware type and model.
Cache Config Amount of physical storage that is installed in this storage subsystem.
Cache Avail Amount of storage that is available for caching. This is the total cache size minus the amount used by the subsystem for the cache directory, minus the amount pinned and offline storage.
Cache Offl Amount of storage that is offline because of a host or subsystem error.
Cache Pinned Amount of storage that is unavailable because a DASD failure is preventing the subsystem from destaging data. The data is pinned in cache.
NVS Overall status of the non-volatile storage (NVS).
Active
NVS is online and usable.
Deact failed
A command requesting deactivation of NVS has been received but transfer from NVS to DASD has failed.
Deact in process
A command requesting deactivation of NVS has been received, and destaging to DASD is still in progress.
Deactivated
NVS has been deactivated by request from host system or support facility.
DFW inhibited
DASD FAST WRITE is inhibited because the battery is defective.
Error termination
An internal error caused termination of NVS.
Maintenance
NVS has been disabled for maintenance by the support facility.
NVS Config Amount of NVS that is installed in this storage subsystem.
NVS Pinned Amount of NVS that is unavailable because a DASD failure is preventing the subsystem from destaging the data. The data is pinned in NVS.
Please refer to Table 2 for a description of the other fields in the pop-up window of the CACHSUM report.