Previous Topic: 3.2.1.5 IBM VTS Virtual Tape Drive Analysis (TAPLVD)Next Topic: 3.2.1.7 IBM VTS Cartridge Use Distribution(TAPLVF)


3.2.1.6 IBM VTS Virtual Tape Mount Analysis (TAPLVE)


The CA 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 section 3.2.1.1.2.
 
The report body reports on the following measurements from
left to right:
 
Interval count and total number of virtual mounts:
 
o Number of Recording Intervals - INTERVLS
o Total Virtual Mounts          - fffTVM
 
Virtual scratch (fast-ready) mount statistics:
 
o Virtual Fast-Ready Mounts         - fffVFRM
o Min Virtual Fast-Ready Mount Time - fffMNFRT
o Avg Virtual Fast-Ready Mount Time - fffAVFMT
o Max Virtual Fast-Ready Mount Time - fffMXFRT
 
Virtual cache hit mount statistics:
 
o Virtual Cache-Hit Mounts          - fffVCHM
o Min Virtual Cache-Hit Mount Time  - fffMNCHT
o Avg Virtual Cache-Hit Mount Time  - fffAVHMT
o Max Virtual Cache-Hit Mount Time  - fffMXCHT
 
Virtual cache miss (recall) mount statistics:
 
o Virtual Recall Mounts             - fffVRM
o Min Virtual Recall Mount Time     - fffMNRMT
o Avg Virtual Recall Mount Time     - fffAVRMT
o 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:
 
o 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:

  o Enter the CA MICS Workstation Facility (MWF)

  o Choose option 2, CA MICS Information Center Facility
    (MICF)

  o Choose option 2, Database Inquiries

  o Select TAPLVE, IBM VTS Virtual Tape Mount Analysis
    Report, whose Catalog Group is PERFORM

  o Complete the MICF Execution panel

  o Complete the specification panel.  Refer to section
    3.2.1.1.1, IBM VTS MICF Inquiry Specification Panels, for
    information about modifiable panel fields.

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.

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% ----------------------------------------------------------------------------------------------------------------------------------

 Figure 3-9.  IBM VTS Virtual Tape Mount Analysis