Cache device activity

The second section of the report contains the same type of information as the Cache Subsystem Overview section, but for only one device. The field contents are explained in Table 3.

Figure 1. Cache Subsystem Activity Report - Cache Device Activity (device-level reporting)

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            z/OS V2R1               SYSTEM ID   SYS1            DATE 09/28/2013            INTERVAL 15.00.055
                                     RPT VERSION V2R1 RMF       TIME 00.30.00

SUBSYSTEM  2105-01     CU-ID  1E91     SSID 3007     CDATE  09/28/2013     CTIME 00.29.55      CINT  15.00
TYPE-MODEL 2105-E20    MANUF  IBM      PLANT  75     SERIAL 000000016374
VOLSER     NP1MHI      NUM    1E85     RRID 0700
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                                                        CACHE DEVICE STATUS
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CACHE STATUS                                       DUPLEX PAIR STATUS

CACHING             - ACTIVE                       DUPLEX PAIR        - NOT ESTABLISHED
DASD FAST WRITE     - ACTIVE                       STATUS             - N/A
PINNED DATA         - NONE                         DUAL COPY VOLUME   - N/A

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                                                       CACHE DEVICE ACTIVITY
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TOTAL I/O    32141   CACHE I/O    32141   CACHE OFFLINE   N/A
TOTAL H/R    0.785   CACHE H/R    0.785

CACHE I/O    -------------READ I/O REQUESTS-------------    ----------------------WRITE I/O REQUESTS----------------------         %
REQUESTS       COUNT     RATE      HITS     RATE     H/R      COUNT     RATE      FAST     RATE      HITS     RATE     H/R      READ

NORMAL         26728     29.6     19998     22.1   0.748          0      0.0         0      0.0          0     0.0     N/A     100.0
SEQUENTIAL      5413      6.0      5241      5.8   0.968          0      0.0         0      0.0          0     0.0     N/A     100.0
CFW DATA           0      0.0         0      0.0     N/A          0      0.0         0      0.0          0     0.0     N/A       N/A

TOTAL          32141     35.6     25239     27.9   0.785          0      0.0         0      0.0          0     0.0     N/A     100.0

-----------------------CACHE MISSES-----------------------            ------------MISC------------          ------NON-CACHE I/O-----
REQUESTS      READ    RATE   WRITE    RATE  TRACKS    RATE                            COUNT   RATE                      COUNT   RATE
                                                                      DFW BYPASS          0    0.0          ICL             0    0.0
NORMAL        6730     7.4       0     0.0    6899     7.6            CFW BYPASS          0    0.0          BYPASS          0    0.0
SEQUENTIAL     172     0.2       0     0.0    6026     6.7            DFW INHIBIT         0    0.0          TOTAL           0    0.0
CFW DATA         0     0.0       0     0.0                            ASYNC (TRKS)        0    0.0

TOTAL         6902    RATE     7.6



---CKD STATISTICS---     ---RECORD CACHING---                         ----HOST ADAPTER ACTIVITY---      --------DISK ACTIVITY-------
                                                                                      BYTES  BYTES               RESP   BYTES  BYTES
WRITE              0     READ MISSES        0                                          /REQ   /SEC               TIME    /REQ   /SEC
WRITE HITS         0     WRITE PROM        28                         READ              736    146      READ   14.132   63.1K 743.9K
                                                                      WRITE           15.9K 471.6K      WRITE  13.812   50.9K 648.1K

Note: In the header of the Cache Device Activity Report, RRID shown for 2105 subsystems is the RAID rank identifier. EXTENT POOL shown for 2107 subsystems is the extent pool identifier.

Table 1. Fields in the Cache Subsystem Activity Report - Cache Device Status
Field Heading	Meaning
CACHE STATUS - Status of the cache from the perspective of the device being reported.
CACHING	Caching status of the device. ACTIVE Caching is active; requests to the reported device can be processed without DASD access. DEACTIVATE PENDING Cache has been deactivated on request from host system or support facility, but transfer of modified data to DASD has failed. DEACTIVATED Caching has been deactivated for the reported device.
DASD FAST WRITE	Status of the DASD FAST WRITE option. ACTIVE DASD FAST WRITE requests can be processed for this device. DEACTIVATION PENDING DASD FAST WRITE has been terminated on request by host system or support facility, but transfer of modified data to DASD is in progress or has failed. DEACTIVATED DASD FAST WRITE requests are ignored for this device.
PINNED DATA	A device has failed, and data that has not yet been written to DASD is pinned in cache or NVS for later recovery. NONE No data is pinned for the reported device. EXISTS, DFW NOT SUSPENDED Pinned data exists, but DASD FAST WRITE has not been suspended. EXISTS, DFW SUSPENDED Pinned data exists, and DASD FAST WRITE has been suspended.
DUPLEX PAIR STATUS - A duplex pair of devices can be established, to ensure a maximum of data security. During normal processing, all I/O requests are made on behalf of the primary device. Data is written to the primary device, either directly or via cache. In either case, the control unit ensures that the data is copied to the secondary device. This happens asynchronously to the transfer from the channel.
DUPLEX PAIR	Overall dual copy status. NOT ESTABLISHED The device is configured as a simplex device. ACTIVE The device reported is either the primary or the secondary device of a duplex pair. PENDING The control unit copies data to establish the duplex pair to which the reported device belongs. SUSPENDED An error in one device of the duplex pair caused the duplex pair to be suspended.
STATUS	The status of this device as part of a duplex pair. PRIMARY The device is the primary device of the duplex pair. All channel operations are associated with this device. SECONDARY The device is the secondary device of the duplex pair. No regular I/O is possible to this device. I/O operations to the primary device are duplexed to this device by the control unit. N/A The device has not been established as part of a duplex pair.
DUAL COPY VOLUME	Identification of the other device of a duplex pair. nnnn Device address of the other device of the duplex pair, if a duplex pair is established. N/A The device has not been established as part of a duplex pair.

The report contains less information for devices which had the cache offline at the end of the interval.

Figure 2. Cache Subsystem Activity Report - Cache Offline

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            z/OS V2R1               SYSTEM ID   SYS1            DATE  09/28/2013       INTERVAL  12.00.000
                                    RPT VERSION V2R1 RMF        TIME  07.12.00

SUBSYSTEM  3990-06     CU-ID  02A0     SSID  0016     CDATE  09/28/2013    CTIME  07.11.55     CINT  12.00
TYPE-MODEL 9396-001    MANUF  IBM      PLANT  92      SERIAL 000000012345
VOLSER     RZ3381      NUM    02B6     RRID  N/A
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                                                         CACHE DEVICE STATUS
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CACHE STATUS                                       DUPLEX PAIR STATUS

CACHING             - DEACTIVATED                  DUPLEX PAIR NOT ESTABLISHED
DASD FAST WRITE     - DEACTIVATED
PINNED DATA         - NONE

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                                                        CACHE DEVICE ACTIVITY
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TOTAL I/O     ---     CACHE I/O     ---     CACHE OFFLINE     8772
TOTAL H/R     ---     CACHE H/R     ---