The CA MICS StorageTek VSM Virtual Tape Mount Report is
created from measurements in the Virtual Tape Volume Mount
Activity (SVTVMR) file. The report displays the number of
scratch and specific mounts requested by the systems attached
to the StorageTek VSM. Most importantly, the report displays
the buffer hit percentage for specific mounts and the delay
in satisfying the mount when a VTV has to be recalled from a
physical cartridge.
The report body displays the following measurements:
o Total virtual mounts (VMRCOUNT)
o Total virtual scratch Mounts (VMRSMT)
o Total virtual specific Mounts (VMREXT)
o Percentage of mounts that were specific (VMRPCEXT)
o Total time to satisfy virtual mounts (VMRMTM)
o Minimum time to satisfy a virtual mount (VMRMNMTM)
o Average time to satisfy a virtual mount (VMRAVMTM)
o Maximum time to satisfy a virtual mount (VMRMXMTM)
Metrics for specific virtual mounts contain statistics on
those that were still found in the disk buffer (buffer hit)
and those that needed to be recalled from real tape (buffer
miss):
o Total specific mounts still found in the disk buffer
(derived during report generation, VMREXT-VMRMRC)
o Minimum mount time of buffer hit specific mounts
(VMRMNHTM)
o Average mount time of buffer hit specific mounts
(VMRAVHTM)
o Maximum mount time of buffer hit specific mounts
(VMRMXHTM)
o Total specific mounts not found in the disk buffer
(VMRMRC)
o Total mount time of specific mounts requiring recall
(VMRXTM)
o Minimum mount time of buffer miss specific mounts
(VMRMNXTM)
o Average mount time of buffer miss specific mounts
(VMRAVXTM)
o Maximum mount time of buffer miss specific mounts
(VMRMXXTM)
o Percentage of specific mounts requiring recall (VMRPCMIS)
USAGE CONSIDERATIONS:
Virtual tape volumes that are resident in the disk buffer can
be mounted practically instantaneously. This provides the
maximum serviceability to the production jobs with no delay.
When virtual tape volumes are not resident in the disk
buffer, the volume must be recalled from real tape to the
disk buffer. The delay here may be significant. The tape
robot needs to retrieve the cartridge containing the virtual
volume, mount it in a drive, and copy all the data back to
the disk buffer before the virtual mount is satisfied. Robot
arm contention, drive contention, and amount of data to copy
back to the disk buffer are all delay factors.
The user will be able to notice the periods of time in this
report where the buffer miss counts are getting close to
unacceptable limits. Monitoring this report over time will
show trends that will allow the user to drill into the
database at those specific times to retrieve additional
information on the affected jobs.
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 TAPLSA, whose Catalog Group is PERFORM
o Complete the MICF Execution panel
o Complete the specification panel. Refer to section
3.2.2.1, StorageTek VSM MICF Inquiry Specification
Panels, for information about modifiable panel fields.
The following report sample shows virtual tape mount metrics
by hour within a week.
Inquiry : TAPLVF IBM VTS Cartridge Use Distribution 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 +------------- Number of Cartridges Containing the Indicated Percentage of Active Data -----------+ Avg Numb | < | Active Reclaim HOUR Intv <=05 <=10 <=15 <=20 <=25 <=30 <=35 <=40 <=45 <=50 <=55 <=60 <=65 <=70 <=75 <=80 <=85 <=90 <=95 =100 Carts Thrsh % ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------ ------- 0 1 1 0 2 0 0 1 16 243 169 113 80 66 53 40 25 19 21 22 30 29 930 n/a 1 1 1 0 2 0 0 1 16 243 169 113 80 66 53 40 25 19 21 22 30 30 931 n/a 2 1 1 0 2 0 0 2 14 243 169 113 80 66 53 40 25 19 21 22 30 31 931 n/a 3 1 1 1 0 0 1 1 13 243 169 113 80 66 53 40 25 19 21 22 30 32 930 n/a 4 1 0 1 2 0 1 0 11 243 169 113 80 66 53 40 25 19 21 22 30 32 928 n/a 5 1 1 0 1 1 1 1 8 243 169 113 80 66 53 40 25 19 21 22 30 33 927 n/a 6 1 1 1 0 2 0 0 7 243 169 113 80 66 53 40 25 19 21 22 30 34 926 n/a 7 1 0 1 2 0 1 0 5 243 169 113 80 66 53 40 25 19 21 22 30 35 925 n/a 8 1 1 0 1 0 2 0 5 246 165 114 80 66 54 39 26 19 23 22 29 33 925 n/a 9 1 0 0 0 0 0 0 7 250 161 119 76 66 56 34 28 22 21 21 28 32 921 n/a 10 1 0 0 1 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 30 921 n/a 11 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 31 921 n/a 12 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 32 922 n/a 13 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 32 922 n/a 14 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 32 922 n/a 15 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 32 922 n/a 16 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 32 922 n/a 17 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 33 923 n/a 18 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 33 923 n/a 19 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 33 923 n/a 20 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 34 924 n/a 21 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 34 924 n/a 22 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 34 924 n/a 23 1 0 0 0 0 0 0 6 250 161 122 74 66 56 34 29 21 20 24 27 34 924 n/a ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------ ------- Avgs 1 0 0 1 0 0 0 8 248 164 119 76 66 55 36 28 20 21 23 28 32 925 n/a ----------------------------------------------------------------------------------------------------------------------------------
Figure 3-12. StorageTek VSM Virtual Tape Mount Report
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