TAP IBM VTS Virtual Tape Mount Analysis (TAPLVE)

The
MICS
IBM VTS Virtual Tape Mount Analysis Report displays statistics for the virtual tape mounts satisfied by the VTS. The report provides the total number of virtual tape mounts with three sets of statistics for each mount type; scratch (fast-ready), cache hit, and cache miss (recall). The final two report columns show the percent of specific virtual mount requests that were cache misses, both as a number and a graphic. At a glance, this graphic shows periods where excessive cache misses occur. Cache misses result in degraded virtual tape performance.
micsrm140
The
MICS
IBM VTS Virtual Tape Mount Analysis Report displays statistics for the virtual tape mounts satisfied by the VTS. The report provides the total number of virtual tape mounts with three sets of statistics for each mount type; scratch (fast-ready), cache hit, and cache miss (recall). The final two report columns show the percent of specific virtual mount requests that were cache misses, both as a number and a graphic. At a glance, this graphic shows periods where excessive cache misses occur. Cache misses result in degraded virtual tape performance.
The report uses both the distributed and composite VTS headers, based on the VTS type reported. These headers and their content are described in IBM VTS Report Headers in IBM VTS MICF Inquiry General Information.
The report body reports on the following measurements from left to right:
Interval count and total number of virtual mounts:
  • Number of Recording Intervals - INTERVLS
  • Total Virtual Mounts - fffTVM
Virtual scratch (fast-ready) mount statistics:
  • Virtual Fast-Ready Mounts - fffVFRM
  • Min Virtual Fast-Ready Mount Time - fffMNFRT
  • Avg Virtual Fast-Ready Mount Time - fffAVFMT
  • Max Virtual Fast-Ready Mount Time - fffMXFRT
Virtual cache hit mount statistics:
  • Virtual Cache-Hit Mounts - fffVCHM
  • Min Virtual Cache-Hit Mount Time - fffMNCHT
  • Avg Virtual Cache-Hit Mount Time - fffAVHMT
  • Max Virtual Cache-Hit Mount Time - fffMXCHT
Virtual cache miss (recall) mount statistics:
  • Virtual Recall Mounts - fffVRM
  • Min Virtual Recall Mount Time - fffMNRMT
  • Avg Virtual Recall Mount Time - fffAVRMT
  • Max Virtual Recall Mount Time - fffMXRMT
Percentage of specific mounts that were cache misses, resulting in the recall of a virtual tape from a physical cartridge. This value is displayed as both a percentage and a graphic:
  • Pct Virtual Specific Mount Cache Misses - fffPCVMS
At the bottom of the report, a line is generated that shows summary totals, minimums, maximums, averages, or percentages as appropriate for the detailed data in each column.
Report data for VTS type COMPOSITE is generated from the VTS Composite Library Activity (IVTVCL) file. Report data for VTS types UI, SECONDARY, and STANDALONE is generated from the VTS Distributed Library Activity (IVTVDL) file.
To produce the report:
  1. Enter the
    MICS Workstation Facility
    (MWF)
  2. Choose option 2,
    MICS Information Center Facility
    (MICF)
  3. Choose option 2, Database Inquiries
  4. Select TAPLVE, IBM VTS Virtual Tape Mount Analysis Report, whose Catalog Group is PERFORM
  5. Complete the MICF Execution panel
  6. Complete the specification panel. For information about modifiable panel fields, see IBM VTS MICF Inquiry Specification Panels in IBM VTS MICF Inquiry General Information.
IBM VTS Virtual Tape Mount Analysis (TAPLVE) Report Sample
The following report sample shows the virtual tape mount activity for a day by hour. The VTS reported is a peer-to-peer configuration. The three report pages show the Composite VTS statistics followed by statistics for the User Interface (UI) and Secondary VTSs.
It is interesting that immediately following the low utilization hours of 11:00 AM to 12:00 noon, the percentage of specific mount requests that result in DASD cache misses increases dramatically. By 2:00 PM, both the peak workload and peak percent misses is reached. The time required to satisfy a mount that requires a recall is significantly longer than a mount satisfied in cache.
This report sample provides data that should encourage an examination of the z/OS workloads using virtual tape that launch after noon. An effort should be made to increase the probability that the virtual volumes requested are found in the cache.

IBM VTS Virtual Tape Mount Analysis Samples

Inquiry : TAPLVE IBM VTS Virtual Tape Mount Analysis Report Run Date: 02OCTyy Data Presented by Hour within Day Page 001 VTS Library ID: K9200 VTC Preferred I/O : NONE Copy Mode Setting : Mixed Report Start: 29SEPyy:00:00 Library Type : PtP-COMPOSITE VTC Preferred Mast: VTS0 VTC Maint Level : 7414.00 Report End : 29SEPyy:24:00 UI/SEC IDs : K9229/K9230 F/C 4001 Status : Enabled Timespan : DAYS ---------------------------------------------------------------------------------------------------------------------------------- Day: 29SEPyy ----Scratch Mounts---- ------Cache Hit-------- -------Cache Miss------- ------Percent Cache Misses------ (Fast Ready) (Recalls/Stage) 1 Numb Total Scr Min Avg Max Hit Min Avg Max Miss Min Avg Max Pct 2 4 6 8 0 HOUR Intv Mounts Total M:SS M:SS MM:SS Total M:SS MM:SS MM:SS Total MM:SS MM:SS MM:SS Miss 0----0----0----0----0----0 ---- ---- ------ ------ ---- ---- ----- ------ ---- ----- ----- ------ ----- ----- ----- ---- 0 1 551 239 0:01 0:02 0:08 258 0:01 0:02 0:06 54 0:46 2:25 5:20 17% ***** 1 1 749 345 0:01 0:02 0:06 353 0:01 0:03 1:30 51 0:22 2:38 6:15 13% *** 2 1 1476 592 0:01 0:04 0:11 831 0:01 0:03 1:32 53 0:56 3:07 6:04 6% ** 3 1 374 168 0:01 0:03 0:10 160 0:01 0:02 1:31 46 1:32 2:39 7:37 22% ****** 4 1 417 153 0:01 0:02 0:05 212 0:01 0:02 0:36 52 0:01 2:31 5:53 20% ***** 5 1 564 206 0:01 0:02 0:05 327 0:01 0:02 1:42 31 0:06 2:01 4:23 9% ** 6 1 685 119 0:01 0:02 0:06 527 0:01 0:02 0:06 39 0:15 2:00 6:42 7% ** 7 1 710 149 0:01 0:02 0:06 485 0:01 0:02 0:05 76 0:05 2:32 5:35 14% **** 8 1 580 148 0:01 0:02 0:07 327 0:01 0:02 0:15 105 0:24 3:04 9:26 24% ****** 9 1 273 55 0:01 0:02 0:04 140 0:01 0:02 0:04 78 1:26 3:11 7:12 36% ********* 10 1 146 65 0:01 0:02 0:04 54 0:01 0:02 0:03 27 0:51 2:35 5:11 33% ********* 11 1 27 5 0:01 0:02 0:03 21 0:01 0:01 0:03 1 3:03 3:03 3:03 5% * 12 1 45 23 0:01 0:01 0:03 21 0:01 0:01 0:03 1 3:03 3:03 3:03 5% * 13 1 50 26 0:01 0:01 0:03 18 0:01 0:02 0:03 6 0:53 1:22 2:07 25% ******* 14 1 241 16 0:01 0:01 0:04 55 0:01 0:02 0:03 170 0:02 1:17 6:22 76% ******************** 15 1 562 267 0:01 0:03 0:08 182 0:01 0:03 0:38 113 0:03 1:21 5:16 38% ********** 16 1 759 507 0:01 0:05 0:19 166 0:01 0:03 1:33 86 0:03 2:23 5:14 34% ********* 17 1 692 472 0:01 0:04 0:11 139 0:01 0:03 0:10 81 0:07 2:59 8:58 37% ********** 18 1 641 359 0:01 0:03 0:10 215 0:01 0:03 0:16 67 0:58 2:38 5:12 24% ****** 19 1 1066 503 0:01 0:03 0:19 512 0:01 0:02 0:36 51 0:46 2:05 4:58 9% ** 20 1 918 395 0:01 0:03 1:01 481 0:01 0:03 1:13 42 0:48 2:00 6:19 8% ** 21 1 826 370 0:01 0:03 0:07 394 0:01 0:03 1:30 62 0:10 2:14 4:19 14% **** 22 1 586 215 0:01 0:02 0:24 308 0:01 0:02 0:38 63 0:27 2:23 5:11 17% **** 23 1 518 181 0:01 0:02 0:06 268 0:01 0:02 1:30 69 0:44 1:58 4:37 20% ***** ---- ------ ------ ---- ---- ----- ------ ---- ----- ----- ------ ----- ----- ----- ---- Tots 24 13456 5578 0:01 0:03 1:01 6454 0:01 0:02 1:42 1424 0:01 2:18 9:26 18% ----------------------------------------------------------------------------------------------------------------------------------
Inquiry : TAPLVE IBM VTS Virtual Tape Mount Analysis Report Run Date: 02OCTyy Data Presented by Hour within Day Page 001 VTS Library ID: K9229 Library Make-Model: 3584-L22 Lib Maint Level: 534.13 Report Start: 29SEPyy:00:00 Library Type : PtP-UI VTS Cache Size : 1728 GB VTS Maint Level: 749.05 Report End : 29SEPyy:24:00 Composite ID : K9200 F/C 4001 Status : Enabled Timespan : DAYS ---------------------------------------------------------------------------------------------------------------------------------- Day: 29SEPyy ----Scratch Mounts---- ------Cache Hit-------- -------Cache Miss------- ------Percent Cache Misses------ (Fast Ready) (Recalls/Stage) 1 Numb Total Scr Min Avg Max Hit Min Avg Max Miss Min Avg Max Pct 2 4 6 8 0 HOUR Intv Mounts Total M:SS M:SS MM:SS Total M:SS MM:SS MM:SS Total MM:SS MM:SS MM:SS Miss 0----0----0----0----0----0 ---- ---- ------ ------ ---- ---- ----- ------ ---- ----- ----- ------ ----- ----- ----- ---- 0 1 562 394 0:01 0:01 0:05 141 0:01 0:01 0:04 27 0:02 2:18 5:17 16% **** 1 1 748 535 0:01 0:01 0:03 181 0:01 0:01 0:04 32 0:01 2:09 6:15 15% **** 2 1 1479 961 0:01 0:01 0:07 474 0:01 0:01 1:10 44 0:01 1:42 5:59 8% ** 3 1 383 267 0:01 0:01 0:06 93 0:01 0:02 1:29 23 0:02 2:49 7:36 20% ***** 4 1 423 297 0:01 0:01 0:03 100 0:01 0:01 0:02 26 0:01 2:11 4:26 21% ***** 5 1 573 384 0:01 0:01 0:03 170 0:01 0:01 1:28 19 0:03 1:49 4:22 10% *** 6 1 689 384 0:01 0:01 0:03 256 0:01 0:01 0:03 49 0:01 0:56 6:40 16% **** 7 1 715 408 0:01 0:01 0:03 252 0:01 0:01 0:03 55 0:01 1:32 4:26 18% ***** 8 1 580 359 0:01 0:01 0:04 162 0:01 0:01 0:14 59 0:01 2:42 9:25 27% ******* 9 1 274 179 0:01 0:01 0:02 59 0:01 0:01 0:03 36 1:25 3:21 7:11 38% ********** 10 1 145 100 0:01 0:01 0:03 30 0:01 0:01 0:02 15 0:01 2:39 5:10 33% ********* 11 1 27 15 0:01 0:01 0:02 6 0:01 0:01 0:02 6 0:01 0:31 3:02 50% ************* 12 1 45 30 0:01 0:01 0:02 14 0:01 0:01 0:02 1 3:01 3:01 3:01 7% ** 13 1 50 29 0:01 0:01 0:01 17 0:01 0:01 0:02 4 0:53 1:11 1:30 19% ***** 14 1 242 115 0:01 0:01 0:02 17 0:01 0:01 0:02 110 0:01 1:07 6:21 87% *********************** 15 1 558 371 0:01 0:01 0:05 111 0:01 0:01 0:04 76 0:01 1:06 5:14 41% *********** 16 1 773 618 0:01 0:02 0:10 103 0:01 0:02 1:30 52 0:01 1:50 5:14 34% ********* 17 1 695 585 0:01 0:01 0:05 66 0:01 0:01 0:05 44 0:01 3:06 8:57 40% ********** 18 1 745 589 0:01 0:01 0:06 112 0:01 0:01 0:16 44 0:01 2:25 6:16 28% ******* 19 1 1072 831 0:01 0:01 0:08 216 0:01 0:01 0:07 25 0:01 2:00 4:57 10% *** 20 1 936 658 0:01 0:01 0:58 244 0:01 0:02 1:12 34 0:01 1:25 6:18 12% *** 21 1 832 590 0:01 0:01 1:29 195 0:01 0:01 0:03 47 0:01 1:28 4:05 19% ***** 22 1 597 374 0:01 0:01 0:22 164 0:01 0:01 0:37 59 0:01 1:22 5:11 26% ******* 23 1 521 332 0:01 0:01 0:04 148 0:01 0:01 0:51 41 0:01 1:40 4:03 22% ****** ---- ------ ------ ---- ---- ----- ------ ---- ----- ----- ------ ----- ----- ----- ---- Tots 24 13664 9405 0:01 0:01 1:29 3331 0:01 0:01 1:30 928 0:01 1:49 9:25 22% ----------------------------------------------------------------------------------------------------------------------------------
Inquiry : TAPLVE IBM VTS Virtual Tape Mount Analysis Report Run Date: 02OCTyy Data Presented by Hour within Day Page 001 VTS Library ID: K9230 Library Make-Model: 3584-L22 Lib Maint Level: 534.13 Report Start: 29SEPyy:00:00 Library Type : PtP-SECONDARY VTS Cache Size : 1728 GB VTS Maint Level: 749.05 Report End : 29SEPyy:24:00 Composite ID : K9200 F/C 4001 Status : Enabled Timespan : DAYS ---------------------------------------------------------------------------------------------------------------------------------- Day: 29SEPyy ----Scratch Mounts---- ------Cache Hit-------- -------Cache Miss------- ------Percent Cache Misses------ (Fast Ready) (Recalls/Stage) 1 Numb Total Scr Min Avg Max Hit Min Avg Max Miss Min Avg Max Pct 2 4 6 8 0 HOUR Intv Mounts Total M:SS M:SS MM:SS Total M:SS MM:SS MM:SS Total MM:SS MM:SS MM:SS Miss 0----0----0----0----0----0 ---- ---- ------ ------ ---- ---- ----- ------ ---- ----- ----- ------ ----- ----- ----- ---- 0 1 545 399 0:01 0:01 0:03 116 0:01 0:01 0:04 30 0:46 2:32 4:32 21% ***** 1 1 807 600 0:01 0:01 1:29 179 0:01 0:01 0:05 28 0:02 2:35 4:29 14% **** 2 1 1416 1074 0:01 0:01 0:04 309 0:01 0:01 0:05 33 0:01 2:22 6:03 10% *** 3 1 509 387 0:01 0:01 1:27 94 0:01 0:02 1:30 28 1:05 2:46 5:16 23% ****** 4 1 374 247 0:01 0:01 0:02 98 0:01 0:01 0:03 29 0:01 2:08 5:53 23% ****** 5 1 475 342 0:01 0:01 0:03 111 0:01 0:01 0:03 22 0:33 1:59 3:54 17% **** 6 1 746 458 0:01 0:01 0:03 255 0:01 0:01 0:03 33 0:01 1:19 4:23 11% *** 7 1 685 436 0:01 0:01 0:03 207 0:01 0:01 0:04 42 0:01 1:36 5:34 17% **** 8 1 654 414 0:01 0:01 0:03 169 0:01 0:01 0:03 71 0:01 2:18 5:28 30% ******** 9 1 247 150 0:01 0:01 0:02 52 0:01 0:01 0:03 45 1:38 2:49 4:30 46% ************ 10 1 243 154 0:01 0:01 0:02 67 0:01 0:01 0:03 22 0:50 2:35 3:54 25% ****** 11 1 31 20 0:01 0:01 0:02 11 0:01 0:01 0:01 0 0:00 . 0:00 0% 12 1 46 39 0:01 0:01 0:01 7 0:01 0:01 0:02 0 0:00 . 0:00 0% 13 1 41 38 0:01 0:01 0:01 1 0:01 0:01 0:01 2 1:19 1:42 2:06 67% ***************** 14 1 205 120 0:01 0:01 0:02 8 0:01 0:01 0:02 77 0:01 1:02 3:18 91% ************************ 15 1 376 299 0:01 0:01 0:05 23 0:01 0:01 0:04 54 0:02 1:17 3:03 70% ****************** 16 1 802 670 0:01 0:01 0:05 80 0:01 0:01 0:03 52 0:01 1:14 3:14 39% ********** 17 1 773 674 0:01 0:01 0:06 59 0:01 0:01 0:06 40 0:01 2:49 5:01 40% *********** 18 1 751 596 0:01 0:01 0:04 105 0:01 0:01 0:03 50 0:01 2:17 5:11 32% ******** 19 1 853 641 0:01 0:01 0:25 181 0:01 0:01 0:03 31 0:01 1:52 3:31 15% **** 20 1 1087 722 0:01 0:01 0:04 318 0:01 0:01 0:04 47 0:01 0:53 3:03 13% *** 21 1 815 613 0:01 0:01 0:04 173 0:01 0:01 0:03 29 0:01 2:13 4:18 14% **** 22 1 650 476 0:01 0:01 0:04 136 0:01 0:01 0:03 38 0:01 2:01 5:09 22% ****** 23 1 535 384 0:01 0:01 1:29 121 0:01 0:01 0:04 30 0:01 1:56 4:36 20% ***** ---- ------ ------ ---- ---- ----- ------ ---- ----- ----- ------ ----- ----- ----- ---- Tots 24 13666 9953 0:01 0:01 1:29 2880 0:01 0:01 1:30 833 0:00 1:56 6:03 22% ----------------------------------------------------------------------------------------------------------------------------------