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OpenVMS System Management Utilities Reference
Manual
The cache hits and misses reflect the effectiveness of file system
caching. Generally, the size of the cache affects the hit rate. The
Attempt Rate is the sum of hits plus misses; the Hit% is the percentage
of attempts that were successful.
Unlike other MONITOR data items, the averages for the hit percentages
are not calculated based on previous hit percentages. Instead, these
values are calculated based on the total number of hits and the total
number of attempts on a cache since the beginning of the Monitor
request. This provides more accurate average values for the hit
percentage items.
The directory FCB cache is checked whenever a
directory lookup is performed. Directory lookups can be performed on
file open, creation, deletion, extension, or truncation. If the file
control block associated with the directory is found in the cache, a
hit is recorded. Otherwise, a miss is recorded. Both hits and misses
are counted as attempts.
The directory data cache is checked whenever a file
lookup is performed. Directory lookups may be performed on file open,
creation, deletion, extension, or truncation. If an entry for the file
being accessed is found in the directory data cache, a hit is recorded.
Otherwise, a miss is recorded. Both hits and misses are counted as
attempts.
The file header cache is checked on file open, close,
creation, deletion, extension, or truncation. If the file header for
the file being accessed is found in the file header cache, a hit is
recorded. Otherwise, a miss is recorded. Both hits and misses are
counted as attempts.
The file identification cache is a list of file
identifiers that are removed on file creation and returned on file
deletion. The File ID hits indicate file numbers successfully removed
or returned to the file ID cache. Otherwise, a miss is recorded. Both
hits and misses are counted as attempts.
The extent cache is checked on file creation,
deletion, extension, and truncation. An attempt is made to allocate
space from the extent cache during file creation or extension. During
file creation, if sufficient size is found, a hit is recorded. If the
desired size is not found, or an entry is forced to be split, an
attempt is recorded. During file deletion, if the blocks were returned
to the cache without the extent cache becoming too large, a hit is
recorded. Otherwise, a miss is recorded. Both hits and misses are
counted as attempts.
If quota checking is enabled, the quota cache is
checked on file creation, deletion, extension, and truncation. If the
desired entry (the identifier matching that of the requester) is found
in the quota cache, a hit is recorded. Otherwise, a miss is recorded.
Both hits and misses are counted as attempts.
The bitmap cache contains blocks from the storage
bitmap file. This cache is accessed when the extent cache cannot
satisfy requests for disk space. High rates indicate fragmented volumes.
Data items in the FILE_SYSTEM_CACHE display correspond to SYSGEN
ACP/XQP parameters, as follows:
| FILE_SYSTEM_CACHE Item |
ACP/XQP Parameters |
|
Dir FCB
|
ACP_SYSACC
|
|
|
ACP_DINDXCACHE
|
|
Dir Data
|
ACP_DIRCACHE
|
|
File Hdr
|
ACP_HDRCACHE
|
|
File ID
|
ACP_FIDCACHE
|
|
Extent
|
ACP_EXTCACHE
|
|
|
ACP_EXTLIMIT
|
|
Quota
|
ACP_QUOCACHE
|
|
Bitmap
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ACP_MAPCACHE
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When you change the ACP/XQP cache parameters, remember to reboot the
system to make the changes effective. For more information about these
parameters, refer to Appendix J.
MONITOR IO
The MONITOR IO command initiates monitoring of the I/O class.
Format
MONITOR IO
Command Qualifiers
/qualifier[,...]
One or more qualifiers as described in the Command Qualifier
Descriptions section.
Classname Qualifiers
/ALL
Specifies that a table of all available statistics (current, average,
minimum, and maximum) is to be included in the display and summary
output. For summary output, this qualifier is the default for all
classes; otherwise, it is the default for all classes except CLUSTER,
MODES, PROCESSES, STATES, SYSTEM, and VECTOR.
/AVERAGE
Specifies that a bar graph of average statistics is to be included in
the display and summary outputs.
/CURRENT
Specifies that a bar graph of current statistics is to be included in
the display and summary outputs. The /CURRENT qualifier is the default
for the CLUSTER, MODES, STATES, SYSTEM, and VECTOR classes.
/MAXIMUM
Specifies that a bar graph of maximum statistics is to be included in
the display and summary outputs.
/MINIMUM
Specifies that a bar graph of minimum statistics is to be included in
the display and summary outputs.
Description
The IO class includes the following data items:
| Data Item |
Description |
|
Direct I/O Rate
|
Rate of direct I/O (for example, disk and tape) operations
|
|
Buffered I/O Rate
|
Rate of buffered I/O (for example, terminal and line printer) operations
|
|
Mailbox Write Rate
|
Rate of write-to-mailbox requests received by the system
|
|
Split Transfer Rate
|
Rate at which transfers were split into multiple I/Os
|
|
Log Name Translation Rate
|
Rate of logical name translations
|
|
File Open Rate
|
Rate at which files were opened
|
|
Page Fault Rate
|
Rate of occurrence of page faults for all working sets
|
|
Page Read Rate
|
Rate of pages read from disk as a result of page faults
|
|
Page Read I/O Rate
|
Rate of read I/O operations from disk as a result of page faults
|
|
Page Write Rate
|
Rate of pages written to the page file
|
|
Page Write I/O Rate
|
Rate of write I/O operations to the page file
|
|
Inswap Rate
|
Rate at which working sets were read into memory from the swap file
|
|
Free List Size
|
Number of pages on the free page list
|
|
Modified List Size
|
Number of pages on the modified page list
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Example
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MONITOR> MONITOR /RECORD IO
OpenVMS Monitor Utility
I/O SYSTEM STATISTICS
on node SAMPLE
29-APR-2000 22:22:44
CUR AVE MIN MAX
Direct I/O Rate 15.33 4.46 0.33 15.33
Buffered I/O Rate 24.91 47.47 24.91 69.00
Mailbox Write Rate 0.00 0.45 0.00 2.95
Split Transfer Rate 1.66 1.56 0.33 3.97
Log Name Translation Rate 13.28 10.75 3.66 27.66
File Open Rate 1.66 1.26 0.33 2.98
Page Fault Rate 24.58 52.31 17.33 178.00
Page Read Rate 12.29 9.00 0.00 26.88
Page Read I/O Rate 2.65 2.43 0.00 6.22
Page Write Rate 0.00 6.69 0.00 58.66
Page Write I/O Rate 0.00 0.27 0.00 1.66
Inswap Rate 0.00 0.00 0.00 0.00
Free List Size 3621.00 3604.09 3392.00 3771.00
Modified List Size 49.00 73.36 4.00 181.00
RECORDING
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This example shows that the direct I/O rate is currently at its highest
level since the MONITOR command was entered and is significantly higher
than the average rate. Termination of this command by Ctrl/C and entry
of a MONITOR PROCESSES/TOPDIO command would show the top users of
direct I/Os. Note that if I/O monitoring is begun at a later time, a
new MONITOR request is defined. That is, it is not a continuation of
the original request; the average, minimum, and maximum statistics are
reinitialized. However, because the original request specified
recording, that data can be played back for redisplay or summarization.
MONITOR LOCK
The MONITOR LOCK command initiates monitoring of the LOCK class.
Format
MONITOR LOCK
Command Qualifiers
/qualifier[,...]
One or more qualifiers as described in the Command Qualifier
Descriptions section.
Classname Qualifiers
/ALL
Specifies that a table of all available statistics (current, average,
minimum, and maximum) is to be included in the display and summary
output. For summary output, this qualifier is the default for all
classes; otherwise, it is the default for all classes except CLUSTER,
MODES, PROCESSES, STATES, SYSTEM, and VECTOR.
/AVERAGE
Specifies that a bar graph of average statistics is to be included in
the display and summary outputs.
/CURRENT
Specifies that a bar graph of current statistics is to be included in
the display and summary outputs. The /CURRENT qualifier is the default
for the CLUSTER, MODES, STATES, SYSTEM, and VECTOR classes.
/MAXIMUM
Specifies that a bar graph of maximum statistics is to be included in
the display and summary outputs.
/MINIMUM
Specifies that a bar graph of minimum statistics is to be included in
the display and summary outputs.
Description
The LOCK class includes the following data items:
| Data Item |
Description |
|
New ENQ Rate
|
Rate of new lock (ENQ) requests (as opposed to conversions)
|
|
Converted ENQ Rate
|
Rate of lock (ENQ) conversion requests
|
|
DEQ Rate
|
Rate of unlock (DEQ) requests
|
|
Blocking AST Rate
|
Rate of lock manager blocking ASTs delivered
|
|
ENQs Forced To Wait Rate
|
Rate of occurrence of locks that could not be granted immediately, thus
causing a wait
|
|
ENQs Not Queued Rate
|
Rate of occurrence of locks that could not be granted immediately but
requested not to be queued, and thus received an error status instead
|
|
Deadlock Search Rate
|
Rate at which a deadlock search was performed
|
|
Deadlock Find Rate
|
Rate at which deadlocks were found
|
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Total Locks
|
Total number of locks in the system
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Total Resources
|
Total number of resources in the system
|
Example
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MONITOR> MONITOR /RECORD IO
MONITOR> MONITOR /INPUT=LOCKSTATS.DAT/SUMMARY/NODISPLAY LOCK/AVERAGE
.
.
.
MONITOR> [Ctrl/Z]
$ TYPE MONITOR.SUM
OpenVMS Monitor Utility
+-----+ LOCK MANAGEMENT STATISTICS
| AVE | on node SAMPLE From: 29-APR-2000 08:00:00
+-----+ SUMMARY To: 29-APR-2000 17:00:00
0 5 10 15 20
+ - - - - + - - - - + - - - - + - - - - -+
New ENQ Rate 2 |****
Converted ENQ Rate 1 |**
| | | | |
DEQ Rate 3 |******
Blocking AST Rate |
| | | | |
ENQs Forced To Wait Rate |
ENQs Not Queued Rate |
| | | | |
Deadlock Search Rate |
Deadlock Find Rate |
| | | | |
Total Locks 3 |******
Total Resources 3 |******
| | | | |
+ - - - - + - - - - + - - - - + - - - - -+
PLAYBACK SUMMARIZING
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This example shows the average use of the lock management subsystem
during a typical workday, based on data that was previously recorded.
MONITOR MODES
The MONITOR MODES command initiates monitoring of the MODES class,
which includes a data item for each mode of processor operation.
Format
MONITOR MODES
Command Qualifiers
/qualifier[,...]
One or more qualifiers as described in the Command Qualifier
Descriptions section.
Classname Qualifiers
/ALL
Specifies that a table of all available statistics (current, average,
minimum, and maximum) is to be included in the display and summary
output. For summary output, this qualifier is the default for all
classes; otherwise, it is the default for all classes except CLUSTER,
MODES, PROCESSES, STATES, SYSTEM, and VECTOR.
/AVERAGE
Specifies that a bar graph of average statistics is to be included in
the display and summary outputs.
/CPU
/NOCPU [=(x[,...])] (default)
In multiprocessor configurations, selects the CPU-specific form of
output, where x specifies the CPU identification. If you
specify /CPU without specifying a CPU identification, MONITOR displays
MODES class statistics for each successive CPU until information for
all active CPUs has been displayed. MONITOR then repeats the cycle
beginning with the first CPU. If you specify one CPU identification,
MONITOR displays statistics for that CPU only. If you specify multiple
CPU identifications, MONITOR displays statistics for each successive
CPU specified, then repeats the cycle beginning with the first
specified CPU.
Note that if you specify multiple CPU identifications, MONITOR does not
notify you if one or more of the specified CPUs is unavailable. If all
of the CPU identifications that you specify do not exist, then MONITOR
will behave as if /CPU were specified without any arguments.
For multiprocessor systems, /NOCPU produces a single modes screen that
reflects the combined time that all CPUs spent in each mode.
For nonmultiprocessor systems, the /CPU qualifier displays the CPU ID;
/NOCPU does not display the CPU ID.
/CURRENT
Specifies that a bar graph of current statistics is to be included in
the display and summary outputs. The /CURRENT qualifier is the default
for the CLUSTER, MODES, STATES, SYSTEM, and VECTOR classes.
/MAXIMUM
Specifies that a bar graph of maximum statistics is to be included in
the display and summary outputs.
/MINIMUM
Specifies that a bar graph of minimum statistics is to be included in
the display and summary outputs.
/PERCENT
/NOPERCENT (default)
Controls whether statistics are expressed as percent values in display
and summary outputs. The [NO]PERCENT qualifier is applicable only to
the DISK, MODES, SCS, and STATES classes.
Description
The following data items, included in the MODES class, can be displayed
as percentages of all processor (CPU) time or as rates of clock ticks
(10 millisecond units) per second:
| Data Item |
Description |
|
Interrupt Stack (Interrupt State on Alpha systems)
|
Time spent on the interrupt stack (on VAX systems) or in an interrupt
state on a kernel stack (on Alpha systems).
|
|
MP Synchronization
|
Time spent synchronizing multiple CPUs (applicable to multiprocessor
systems only).
|
|
Kernel Mode
|
Time spent in kernel mode, but not in an interrupt state.
|
|
Executive Mode
|
Time spent in executive mode.
|
|
Supervisor Mode
|
Time spent in supervisor mode.
|
|
User Mode
|
Time spent in user mode executing instructions.
|
|
Compatibility Mode
|
Time spent executing compatibility mode instructions. (This data item
is meaningful only for VAX systems.)
|
|
Idle Time
|
Time not spent in any of the other modes.
|
For multiprocessor systems, when you enter the MONITOR MODES command
without using the /CPU qualifier to select specific CPUs, MONITOR
produces a single modes screen similar to those produced for
nonmultiprocessor systems. However, the statistics produced for
multiprocessor systems reflect the combined time that all CPUs spent in
each mode.
Examples
| #1 |
MONITOR> MONITOR MODES /PERCENT
OpenVMS Monitor Utility
TIME IN PROCESSOR MODES (%)
+-----+ on node SAMPLE
| CUR | 29-APR-2000 22:52:42
+-----+
0% 25% 50% 75% 100%
+ - - - - + - - - - + - - - - + - - - - -+
Interrupt Stack 4 |*
| | | | |
MP Synchronization |
| | | | |
Kernel Mode 6 |**
| | | | |
Executive Mode 2 |
| | | | |
Supervisor Mode |
| | | | |
User Mode 72 |***************************
| | | | |
Compatibility Mode |
| | | | |
Idle Time 16 |******
| | | | |
+ - - - - + - - - - + - - - - + - - - - -+
|
|
This display shows that, over the last collection interval, the
processor spent 72 percent of its time executing user code, 8 percent
executing system code to service user requests in executive and kernel
modes, and 4 percent processing interrupts on the interrupt stack. It
was idle 16 percent of the time. Time spent executing OpenVMS RMS code
is included in executive-mode time. Time spent executing DCL code is
included in supervisor-mode time.
If you omit the /PERCENT qualifier or specify /NOPERCENT, MONITOR
displays mode times as rates of clock ticks per second, where a clock
tick is 10 milliseconds. On a uniprocessor, the rate value is
equivalent to the percent value.
| #2 |
MONITOR> MONITOR MODES
OpenVMS Monitor Utility
+-----+ TIME IN PROCESSOR MODES
| CUR | on node SAMPLE
+-----+ 29-APR-2000 15:02:36
Combined for 2 (of 4) CPUs 0 50 100 150 200
+ - - - - + - - - - + - - - - + - - - - -+
Interrupt Stack |
| | | | |
MP Synchronization |
| | | | |
Kernel Mode 2 |*
| | | | |
Executive Mode 1 |*
| | | | |
Supervisor Mode |
| | | | |
User Mode 101 |********************
| | | | |
Compatibility Mode |
| | | | |
Idle Time 96 |******************
+ - - - - + - - - - + - - - - + - - - - -+
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This example demonstrates output of the MONITOR MODES command for a
multiprocessor system. Displayed statistics represent rates of clock
ticks per second. Information in the upper left corner of the screen
indicates that node SAMPLE has four CPUs, two of which are active.
Because the command line does not include the /CPU qualifier,
statistics reflect the combined time that all CPUs spent in each mode.
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