nmon Command

Purpose

Displays local system statistics in interactive mode and records system statistics in recording mode.

Syntax

Interactive mode:

nmon [-h ]

nmon [ -s < seconds > ] [ -c < count > ] [ -b ] [ -B ] [ -g < filename > ] [ -k disklist ] [ -C < process1:process2:..:processN > ] [ -i ]

Recording mode:

nmon [ -f | -F filename | -x | -X | -z ] [ -r < runname > ] [ -t | -T | -Y ] [ -s seconds ] [ -c number ] [ -w number ] [ -l dpl ] [ -d ] [ -g filename ] [ -k disklist ] [ -C <process1:process2:..:processN > ] [ -G ] [ -K ] [ -o outputpath ] [ -D ] [ -E ] [ -J ] [ -V ] [ -P ] [ -M ] [ -N ] [ -W ] [ -S ] [ -^ ] [ -O ] [ -L ] [ -I percent ] [ -A ] [ -m < dir > ] [ -Z priority ] [ -i ] [ -y options ]

Note: In recording mode, specify only one of the -f, -F, -z, -x, or -X flags as the first argument.

Description

The nmon command displays and records local system information. The command can run either in interactive or recording mode. If you specify any of the -F, -f, -X, -x, and -Z flags, the nmon command is in recording mode. Otherwise, the nmon command is in interactive mode.

The nmon command provides the following views in interactive mode:

In the recording mode, the command generates thenmon files. You can view these files directly by opening them or with post processing tools such as nmon analyzer. The nmon tool disconnects from the shell during the recording, ensuring that the command continues running even if you log out.

If you use the same set of keys every time the nmon command is started, you can place the keys in the NMON shell variable. For example, you can run the following command:
export NMON=mcd
Then, run the nmon command.

To stop the nmon command from the command line, use the kill -USR2 with the nmon process ID.

To print the background process IDs of the nmon recording, run the nmon command with the -p flag.

To limit the processes that the nmon command lists (online and to a file), you can utilize the following options:
  • Set the program names in environment variables from NMONCMD0 to NMONCMD63
  • Use the -C flag with cmd:cmd:cmd parameter. For example, you can enter the following command:
    nmon -C ksh:vi:syncd
To limit the disks that the nmon lists to a maximum of 64 (online only), use the -k flag with the diskname parameter. For example, you can enter the following command:
nmon -k hdisk2,hdisk0,hdisk3

The nmon tool disconnects from the shell during the recording, ensuring that the command continues running even if you log out. This function is not true in the case of recordings triggered using the on-demand recording facility.

Recording or monitoring journaled file system (JFS) statistics in nmon can prevent unloading a file system because the file system is in use while collecting statistics.

Inside workload partitions (WPAR), the nmon command shows global values for processors and memory statistics. The rest of the values are WPAR specific. The following statistics cannot be retrieved inside a WPAR, and the nmon screen does not support them inside a WPAR:
  • Disks, disk I/O graphs, disk busy map, disk groups
  • Disk adapters
  • Paging space
  • Volume group
  • ESS/vpaths
  • Fibre Channel adapters
  • VIOS Shared Ethernet adapters
Note: The dynamic configuration changes applied to the system are not reflected in the current nmon recording. The nmon tool must be restarted for the new configuration changes to take effect.

Flags in Interactive Mode

You can use the following flags in the interactive mode.
Item Description
-s < seconds > Time interval between refreshing the screen. The default value is 2 seconds.
-c < count > Number of times the screen must be refreshed.
-g < filename > A file that contains user-defined disk groups that can be specified using the filename parameter. Each line in the file begins with a group name. The list of hard disks follows the group name and is separated by spaces. The file can contain a maximum of 64 disk groups. A hard disk can belong to various disk groups.
-b Displays the view in black and white mode.
-B Does not include boxes in the view. By default, the command displays boxes.
-h Displays help information.
-k < disklist > Reports only the disks in the disk list.
-i Reports top thread level CPU utilization.

Flags in Recording Mode

Item Description
-A Includes the Asynchronous I/O section in the view.
-c Specifies the number snapshots that must be taken by the command. The default value is 10000000.
-d Includes the Disk Service Time section in the view.
-D Skips the Disk Configuration section.
-E Skips the ESS Configuration section.
-f Specifies that the output is in spreadsheet format. By default, the command takes 288 snapshots of system data with an interval of 300 seconds between each snapshot. The name of the output file is in the format of hostname_YYMMDD_HHMM.nmon.
-F Specifies that the output is in spreadsheet format and the name of the output file is filename. The filename parameter specifies the name of the output file.
-g Specifies the file that contains the user-defined disk groups, using the filename parameter. Each line in the file begins with a group name. The list of disks follows the group name and is separated with spaces. The file can contain a maximum of 64 disk groups. A disk can belong to various disk groups.
-G Uses Greenwich mean time (GMT) instead of local time. This method is helpful when you compare nmon files from many LPARof 1 system for processor view but the LPARare in different time zones.
-i Reports thread level statistics.
-I Specifies the percentage of process threshold at which the command ignores the TOP processes statistics. The default percentage is zero. The command does not save the TOP processes statistics if the process is using less processor than the specified percentage.
-J Skips the JFS section.
-k Specifies a list of disks to be recorded.
-K Includes the RAW Kernel section and the LPAR section in the recording file. The -K flag dumps the raw numbers of the corresponding data structure. The memory dump is readable and can be used when the command is recording the data.
-l Specifies the number of disks to be listed on each line. By default, 150 disks are listed per line. For EMC disks, specify a value of 64.
-L Includes the large page analysis section.
-m Changes the directory before the command saves the data to a file.
-M Includes the MEMPAGES section in the recording file. The MEMPAGES section displays detailed memory statistics per page size.
-N Includes the NFS section in the recording file. To collect the NFSv4 statistics, specify -NN.
-o Specifies the file name or directory to which the recorded file is to be stored.
-O Includes the Shared Ethernet adapter (SEA) VIOS sections in the recording file.
-P Includes the Paging Space section in the recording file.
-r Specifies the value for the runname field written to the spreadsheet file. By default, the value is the hostname.
-s Specifies the interval in seconds between 2 consecutive recording snapshots.
-S Includes WLM sections with subclasses in the recording file.
-t Includes the top processes in the output. You cannot specify the -t, -T, or -Y flags with each other.
-T Includes the top processes in the output and saves the command-line arguments into the UARG section. You cannot specify the -t, -T, or -Y flags with each other.
-V Includes disk volume group section.
-w Specifies the size of timestamp (Tnnnn) to be recorded. The timestamp is recorded in the .csv file. The value of the number parameter ranges from 4 through 16. For NMON analyzer, use the values 4 or 8.
-W Includes the WLM sections into the recording file.
-x Specifies the sensible spreadsheet recording for duration of 1 day for capacity planning. By default, the recording is done every 900 seconds for 96 times. This flag is equivalent to -ft -s 900 -c 96.
-X Specifies the sensible spreadsheet recording for duration of 1 hour for capacity planning. By default, the recording is done every 30 seconds for 120 times. This flag is equivalent to -ft -s 30 -c 120.
-y options Controls the nmon recording sections. The values of the options parameter must be separated by commas.
The following values are valid for the options parameter:
PCPU=[on | off ]
Enables or disables recording of Physical CPU (PCPU) sections, which are nothing but metrics that start with PCPU. These metrics are based on Processor Utilization of Resources Register (PURR). The default value is off.
You can specify the following values for the PCPU section:
on
Enables recording of the PCPU section.
off
Disables recording of the PCPU section.
SCPU=[on | off ]
Enables or disables recording of Scaled CPU (SCPU) sections, which are nothing but metrics that start with SCPU. These metrics are based on Scaled Processor Utilization of Resources Register (SPURR). Default value is off.
You can specify the following values for the SCPU section:
on
Enables recording of the SCPU section.
off
Disables recording of the SCPU section.
Note: The latest values of the options parameter override the previous values if the same value is used more than once in the command line.

Example: If you run the command "nmon -f -y PCPU=on -y PCPU=off" , the value off is used for the PCPU option.

-Y Includes the top process in the recording with all of the commands of the same name that are added and recorded. You cannot specify the -t, -T, or -Y flags together.
-z Specifies the sensible spreadsheet recording for duration of 1day for capacity planning. By default, the recording is done every 900 seconds for 96 times. This flag is equivalent to -f -s 900 -c 96.
-Z Specifies the priority of the nmon command that is running. A value of -20 means important. A value of 20 means not important. Only root user can specify negative value.
-^ Includes the Fibre Channel (FC) sections.

Parameters

Item Description
disklist Specifies a list of disks.
dir Specifies a directory.
dpl Specifies the number of disks to list on each line.
filename Specifies a file that contains the disk group you select.
number Specifies the number of refreshes.
count Specified the number of times to record.
percent Specifies the percentage of processor usage.
priority Specifies the priority of processes to be run.
runname Specifies the value for the runname field in the spreadsheet file to be run.
seconds Specifies the interval, in seconds, of refreshing the snapshot.
outputpath Specifies the path for the output file.

Subcommands

Item Description
space Refreshes the screen immediately.
. Displays only busy disks and processes.
~ Switches to the topas screen.
^ Displays the Fibre Channel adapter statistics
+ Doubles the screen refresh time.
- Decreases the screen refresh time by half.
0 Resets the peak values of statistics (displayed on the screen) to zero. Applicable only for panels that display peak values.
a Displays the I/O statistics of the adapters.
A Summarizes the Async I/O (AIO server) processes.
b Displays the view in black and white mode.
c Displays processor statistics with bar graphs.
C Displays processor statistics. It is useful for comparison when the number of processors ranges from 15 to 128.
d Displays the I/O information of disks. To display specific disks only, specify the -k flag.
D Displays the I/O statistics of disks. To get additional statistics of the disks, press the D key more than once.
e Displays the I/O statistics of the ESS virtual path logical disks.
g Displays the I/O statistics of the Disk Group. You must specify the -g flag with this key.
h Displays the online help information.
j Displays the JFS statistics.
k Displays the internal statistics of the kernel.
l Displays the processor statistics in long format. More than 75 snapshots are displayed with bar graphs.
m Displays the memory and paging statistics.
M Displays multiple page size statistics in pages. If you press the M key twice, the statistics are displayed in megabytes.
n Displays the network statistics.
N Displays the statistics of the NFS Network file system. If you press the N key twice, you see the NFSv4 statistics.
o Displays the map of Disk I/O.
O Displays only the Shared Ethernet adapter VIOS.
p Displays the statistics of the partitions.
P Displays the statistics of the paging space.
q Quits. You can also use the x, or Ctrl+C key sequence.
r Displays the resource type, system name, cache details, AIX® version, and the LPAR information.
S Displays the WLM with subclasses.
t Displays the statistics of top processes. You can press the following keys with this subcommand:
  • 1: Displays basic details.
  • 2: Displays accumulated process information.
  • 3: Sorts the view by processor.
  • 4: Sorts the view by size.
  • 5: Sorts the view by I/O information.
u Displays the top processes with the command arguments. To refresh the arguments for new processes, press the u key twice.
U Displays the top processes with the command arguments, and the workload class or workload partitionworkload partition information.
v Highlights status of pre-defined system resources and categorizes them as either danger, warnings, or normal.
V Displays the statistics of the Disk Volume Group.
w Displays the wait processes when used with the top processes.
W Displays the statistics of the Workload Manager (WLM).
[ Triggers a custom on-demand recording. The recording initiated exits along with the interactive nmon if not stopped earlier.
] Stops a custom recording triggered by ] .

Output Details

This section provides explanations to the metrics that are displayed on nmon screen.

System resources view

This view provides general information about the system resources. To display this view, press the r key. It contains information about the following resources:
  • The number of processors in the system.
  • The number of online processors that are active in the system.
  • The frequency of the processors.
  • The version of AIX and its technical level.
  • The type of the running kernel.
  • The logical partition.
  • The power savings mode of the logical partition.
  • The model of the hardware.
  • The processor architecture of the system.
  • The type of the platform bus.
  • The cache information of processors.
  • The number of active events.
  • The old serial number. This number is the system ID of the partition before the dynamic configuration event.
  • The current serial number. This number is the current system ID or the system ID of the partition after the dynamic configuration event.
  • The local time of the last dynamic reconfiguration event. This information is labeled with the "When" keyword.
  • The sub processor mode of the logical partition.

AIO Processes View

The AIO processes view provides information about the asynchronous I/O (AIO) processes. To display this view, press the A key. The following columns are displayed on the screen:
Item Description
Total AIO Processes The total number of AIO processes.
Actually in use The number of AIO processes that uses more than 0.1% of the processor.
CPU Used The percentage of the processor that is used by all of the kernel processes.
All time peak The maximum number of kernel processes that are running since the system starts.
Recent peak The recent maximum number of kernel processes that use more than 0.1% of the processor.
Peak The maximum percentage of the processor that is used by all of the kernel processes.

Process View

The Process View provides details of the processes in the system. To display this view, press the t key or the v key. It contains the following columns are displayed on the screen:
Item Description
pid The ID of the process.
ppid The ID of the parent process.
User The user ID of the process.
Proc Group The ID of the process group.
Nice The initial priority of a process. This value is set by the nice command.
Priority The base schedule priority of a process.
Status The status of a program.
Proc_Flag The flag of a process.
Thrds The number of threads.
Files The maximum file index that is in use.
Foreground Foreground process or background process.
Command The name of the command.
Time Start The time when the command started.
CPU-Total The total time that the process takes since it starts.
Child Total The total time that the child process takes since it starts.
Delta-Total The total time taken by the process in the interval.
%CPU Used The percentage of the processor that is used in the last interval.
Size KB The size of the pages in kilobytes.
Res Size The sum of real-memory data (resident set) and real-memory (resident set) text size of the process.
Res Set The sum of real-memory data (resident set) and real-memory (resident set) text size of the process.
Res Text The real-memory text size of the process.
Res Data The real-memory data size of the process.
Char I/O The number of I/O characters per second from the last interval.
RAM Use The percentage of the RAM that is used.
Paging I/O The I/O page faults per second in the last interval.
Paging Other The non-I/O page faults per second in the last interval.
Paging Repages The number of repage faults per second in the last interval.
Class The Workload Manager class name of the process.

Processor Usage Small View

The Processor Usage Small View provides a brief summary of the user, system, idle, and wait time of logical processors, the corresponding entitlement, and the virtual processor used. You can generate the Processor Usage Small View using the c key.

Processor Usage Large View

The Processor Usage Large View displays the use of logical processor in a graph. To display this view, you can press the C key.

The following labels are used to identify time that is spent in different modes:
  • s: Labels the percentage of time that is spent in system mode
  • u: Labels the percentage of time that is spent in user mode

Shared-Processor Logical Partition View

The Shared-Processor Logical Partition View includes flags that indicate the following information of a partition:
  • Whether the partition is an LPAR or not
  • Whether the partition can be an LPAR or not
  • Whether the partition is shared or dedicated
  • Whether the SMT is turned on or off
  • Whether the shared-partition is capped or uncapped
  • Whether LPAR the SMT is bound or enabled
  • Whether the LPAR flags are set, and whether they are set to display a value greater than AVG=lp
If the flags are set, the nmon+C graph contains information about the Cpu_user and the Avg_user, respectively. You can view the graph in the right column.

To display this view, you can press the p key.

Processors:

The following metrics of the processor status are displayed in this view:
Item Description
Max Phys in Sys Maximum number of physical processors in the system
Phys CPU in system Number of physical processors in the system
Virtual Online Number of online virtual processors
Logical online Number of online logical processors
Physical pool Number of shared physical processors in the shared pool ID that this partition is assigned to
SMT threads/CPU Number of SMT threads per processor

Capacity:

The following information displays the processor capacity:
Item Description
Cap. Processor Min Minimum number of processing units that are defined for this LPAR
Cap. Processor Max Maximum number of processing units that are defined for this LPAR
Cap. Increment Granularity at which changes to the entitled capacity can be made
Cap. Unallocated Sum of the number of processor units that are unallocated from shared LPARin an LPAR group
Cap. Entitled Entitled capacity
MinReqVirtualCPU Minimum required virtual processors for the LPAR

ID Memory:

The following metrics of the ID memory are displayed:
Item Description
LPAR ID Group:Pool ID of an LPAR group and its pool ID
Memory (MB/GB) Min:Max Minimum and maximum memory that is defined for this LPAR in megabytes or gigabytes
Memory(MB/GB) Online Online real memory in megabytes or gigabytes
Memory Region LMB Size in bytes of one logical memory block (LMB)
Time (in seconds):
Item Description
Time Dispatch Wheel Interval during which each virtual processor receives its entitlement
MaxDispatch Latency Maximum latency in seconds between the dispatch of the LPAR on the physical processors
Time Pool Idle Time in seconds that the shared processor pool is idle
Time Total Dispatch Total time in seconds that the LPAR dispatches

Minimum and Maximum Values of Processors

The following minimum and maximum values of processors are displayed:
Item Description
Virtual CPU ( Min - Max ) Minimum number and maximum number of virtual processors in the LPAR definition
Logical CPU ( Min - Max ) Minimum number and maximum number of logical processors

Weight

The following information about the weight of the processor is displayed:
Item Description
Weight Variable Variable weight of the processor capacity
Weight Unallocated Unallocated variable weight available for this partition

NFS Panel

The NFS Panel provides information about the Network File System (NFS). To display this view, press the N key. The following metrics are included in the view:
Item Description
Root NFS V2 server and client root requests
Wrcache NFS server and client write cache requests
Null NFS server and client write cache requests
Getattr NFS server and client get attributes requests
Setattr NFS server and client set attributes requests
Lookup NFS server and client filename lookup requests
Readlink NFS server and client read link requests
Read NFS server and client read requests
Write NFS server and client write requests
Create NFS server and client file creation requests
Mkdir NFS server and client directory creation requests
Symlink NFS server and client symbolic link creation requests
Remove NFS server and client file removal requests
Rmdir NFS server and client directory removal requests
Rename NFS server and client file renaming requests
Link NFS server and client link creation requests
Readdir NFS server and client read-directory requests
Fsstat NFS server and client file-status requests
Access NFS V3 server and client access requests
Mknod NFS V3 server and client mknod creation requests
readdir+ NFS V3 server and client read-directory plus requests
Fsinfo NFS V3 server and client file information requests
Pathconf NFS V3 server and client path configuration requests
Commit NFS server and client commit requests
Bad calls NFS server and client failed calls
Calls NFS server and client requests
The following NFS V4 client/server statistics are printed when you press the N key twice.
Item Description
Access NFS V4 server and client access requests
acl_read NFS V4 client reading access control list (ACL)
acl_stat_l NFS V4 client that is retrieving long ACL information
acl_write NFS V4 client write access control list (ACL)
Clntconfirm NFS V4 client confirm operations
Close NFS V4 client closing files
Commit NFS V4 server and client committed
Compound NFS V4 server compound calls
Create NFS V4 server and client that is creating a non-regular object
Delegpurge NFS V4 server purge delegations that is awaiting recovery
Delegreturn NFS V4 server and client that is returning delegation
Finfo NFS V4 client that is obtaining file information
getattr NFS V4 server and client retrieving attributes
getfh NFS V4 server retrieving file handles
Link NFS V4 server and client that is linking operations
Lock NFS V4 server and client that is locking operations
lockt/test NFS V4 server that is testing the specified lock or NFS V4 client lock test
locku/unlock NFS V4 server or NFS V4 client unlock operations
lookup NFS V4 server and client that is looking up filenames
lookupp NFS V4 server that is looking up parent directories
mkdir NFS V4 client that is creating directories
mknod NFS V4 client that is creating special files
Null NFS V4 server null calls or NFS V4 client null calls
nverify NFS V4 server verifying difference in attributes
openattr NFS V4 server opening named attribute directories
openconfirm NFS V4 server and client that is confirming the open for usage
opendowngrade NFS V4 server and client that is downgrading the access for a specified file
Open NFS V4 server and client open operations
operations NFS V4 server and client operations
pcl_read NFS V4 client extracting numeric data from printer control language (PCL) files
pcl_readstat_l NFS V4 client pcl_stat long operations
pcl_stat NFS V4 client pcl_stat operations
pcl_write NFS V4 client pcl_write operations
putfh NFS V4 server setting current file handles
putpubfh NFS V4 server setting public file handles
putrootfh NFS V4 server setting root file handles
readdir NFS V4 server and client reading directories
readlink NFS V4 server and client reading symbolic links
Read NFS V4 server and client reading data from files
release NFS V4 server and client release_lock operations
remove NFS V4 server and client removing file system object
rename NFS V4 server and client renaming object names
renew NFS V4 server and client renewing leases
replicate NFS V4 client replicate operations
restorefh NFS V4 server restoring file handles
rmdir NFS V4 client removing directories
savefh NFS V4 server saving file handles
secinfo NFS V4 server and client obtaining security information
setattr NFS V4 server and client setting object attributes
setclient NFS V4 server and client setclient operations
statfs NFS V4 client file statistics requests
symlink NFS V4 client symbolic link operations
verify NFS V4 client verifying same attributes
write NFS V4 server and client writing to files

Network Interface View

The Network Interface View shows the statistics errors for the network. You can view this information by pressing the n key.

If the screen is updated three times with no network errors, the Network Interface View does not contain the network error statistics.

The following metrics are displayed in this view:
Item Description
I/F Name Interface name
Recv-KB/s Data that are received in kilobytes per second in the interval
Trans-KB/s Data that are transmitted in kilobytes per second in the interval
Packin Number of packets that are received in the interval
Packout Number of packets that are sent in the interval
Insize Average size of packet that is received in the interval
Outsize Average size of packet that is sent in last interval
Peak->Recv Peak value of received data in kilobytes per second
Peak->Trans Peak value of sent data in kilobytes per second
Total Recv Total received data in megabytes per second
Total Sent Total sent data in megabytes per second
MTU Maximum size of transport unit in bytes
Ierror Number of input errors
Oerror Number of output errors
Collision Number of collisions
Mbits/s Adapter bit rate in megabits per second. If the network adapter is larger than 10Gb, the adapter bit rate is shown as 10240 Mbits per second.
Description Description of the interface

WLM View

The WLM View displays the information about workload management. You can display this view by using the W key. To turn on the subclasses section, press the S key from WLM View. To turn off the subclasses section, press the S key again.

The following metrics are displayed in this view:
Item Description
CPU Percentage of processor use of the class.
MEM Percentage of physical memory use of the class.
BIO Percentage of disk I/O bandwidth use for the class.
Process (Procs) Number of processes in the class.
Tier (T) Tier number. The value ranges from zero through nine.
Inheritance (I) Values of the inheritance attribute. A value of zero means no. A value of one means yes.
Location Values of location. A value of one means avoiding transfer of segments to shared classes. Otherwise, a value of zero is displayed.

Disk Busy Map

The Disk Busy Map shows the use statistics of disks. To display this map, press the o key. A maximum of 100 disks is shown per screen. Only the disks with the names that range from hdisk0 through hdisk100 are displayed. The following table shows the symbols for the ranges of names.
Symbols Names
_ Less than 5
. Less than 10
- Less than 20
+ Less than 30
o Less than 40
0 Less than 50
O Less than 60
8 Less than 70
X Less than 80
# Less than 90
@ Less than 100 and equal to 100

Disk Groups

Multiple disks can be monitored by placing them in groups. To display this view, press the g key.

You must create a group configuration file that contains the lines as shown in the following example:
<Group_name1> <disk_name1> <disk_name2> ....
<Group_name2> <disk_nameA> <disk_nameB> ... 

In the example, <Group_name1> is the name of the first disk in the group; <disk_name1> and <disk_name2> are the first and second disks in the group.

To see the Disk Group I/O, run the nmon command with the -g flag and a group file, and then press the g key. The following metrics are shown in this view:
Item Description
Name Disk Group name. You can specify a maximum of 64 groups. A disk can be in multiple groups.
Disks Number of disks in the group.
Read/Write-KB/s Data transfer rate of read and written data in kilobytes per second in the interval.
TotalMB/s Sum of read and written data in megabytes per second in the interval.
Xfers/s Number of read and written data transfers per second in the interval.
BlockSizeKB Block size in kilobytes read or written per transfer operation.

ESS Vpath Statistics View

This view provides the ESS Vpath Statistics. To display this view, press the e key. The following metrics are included in this view:
Item Description
Name Name of the virtual path.
Size Size of the ESS path.
AvgBusy Average busy use of the disk.
Write-KB/s Transfer rate of written data in kilobytes per second in the interval.
Read-KB/s Transfer rate of read data in kilobytes per second in the interval.
Xfers/s Number of read and write transfers per second.
Total vpaths Number of virtual paths.

JFS View

This view provides the Journaled File System (JFS) statistics. To display this view, press the j key. The following statistics are recorded in this view:
Item Description
FileSystem Name of the file system.
Size (MB) Size in megabytes for the file system.
Free (MB) Available free space in megabytes in the file system.
%Used Percent of file system used.
%Inodes Percent of file system that is used by i-nodes.
Mount point Local mount point.

Kernel Statistics

This view contains the statistics of the kernel. To display this view, press the k key. The following statistics are displayed in this view:
Item Description
runqueue Average number of threads that are ready to run but are waiting for an available processor.
pswitch Number of processor switches per second in the interval.
fork Number of forks per second in the interval.
exec Number of execs per second in the interval.
msg Number of interprocess communication (IPC) messages that are sent and received per second in the interval.
sem Number of semaphore operation system calls per second in the interval.
hw intrp Number of device interrupts per second in the interval.
sw intrp Number of off-level handlers that are called per second in the interval.
Swapin Number of processes in swap queue per second in the interval.
Syscall Number of system calls per second in the interval.
read Number of read calls per second in the interval.
write Number of write calls per second in the interval.
readch Number of characters that are transferred through read system call per second in the interval.
Writech Number of characters that are transferred through write system call per second in the interval.
R + W (MB/s) Number of read and write characters in megabytes per second in the interval.
Uptime Time duration for which the system is up.
iget Number of inode lookups per second in the interval.
dirblk Number of 512-byte block reads by the directory search routine to locate an entry for a file per second in the interval.
namei Number of vnode lookup from a path name per second in the interval.
ksched Number of kernel processes that are created per second in the interval.
koverf Number of kernel process creation attempts where the user forked to the maximum limit or the configuration limit of processes that are reached per second in the interval.
kexit Number of kernel processes that become zombies per second in the interval.

Long Term Processor Averages View

This view provides information about the instantaneous system. To display this view, press the l key. You can use the following labels to identify the time that is spent in different modes:
  • s: Labels the percentage of the time that is spent in system mode.
  • u: Labels the percentage of the time that is spent in user mode.
  • w: Labels the percentage of the time that is spent in wait mode.
The following metrics are displayed on this view:
Item Description
EntitledCPU Entitled capacity of the partition.
UsedCPU Number of physical processors that are used by the partition.

Large Page Analysis

This view provides analysis of the large page. To display this view, press the L key. The following information is displayed:
Item Description
Count Number of large pages and their total size.
Free Percentage of free large pages and their size.
In Use Percentage of large pages in use and their size.
Size Size of a large page.
High water mark Large page high watermark.

Paging Space

This view prints the paging-space statistics. To display this view, press the p key. The following metrics are displayed in the view:
Item Description
PagingSpace Number of paging spaces.
Volume-Group Number of volume groups.
Type Type of logical volumes. The types can be NFS or LV.
LPs Size of logical partitions.
MB Size in megabytes.
Used Percentage of use for volume groups.
IOpending Number of pending I/O in the paging space.
Active/Inactive Active or inactive paging space.
Auto/NotAuto Indicates whether the paging space is auto that is loaded or not.

Volume Group Statistics

This view provides statistics for the volume group. To display this view, press the V key. The following information is displayed in the view:
Item Description
Name Volume group name.
Disks Number of disks in the group.
AvgBusy Average busy of the disks in the volume group.
Read/Write-KB/s Data transfer rate of read and written data in kilobytes per second in the interval.
TotalMB/s Sum of read and written data in megabytes per second in the interval.
Xfers/s Number of read and written transfers per second in the interval.
BlockSizeKB Block size that is read or written per transfer in kilobytes per second in the interval.

Disk Statistics

This view provides statistics for disks. To display this view, press the D key. You can press the D key for the following times to view various metrics:
  • Once: Shows disk numbers
  • Twice: Shows disk descriptions
  • Three times: Shows service times
  • Four times: Shows disk statistics with graphs similar to the graph shown on pressing the d key

Disk Numbers (pressing the D key once)

The following metrics are shown in this view:
Item Description
Name Name of the disks.
Busy Average busy of the disks.
Read-KB/s Data transfer rate of read data in kilobytes per second in the interval.
Write-KB/s Data transfer rate of written data in kilobytes per second in the interval.
Transfers/sec Number of read and written transfer per second in the interval.
SizeKB Block size that is read or written per transfer in kilobytes per second in the interval.
Peak Peak percentage of average busy.
Peak KB/s Peak that is read and written data in kilobytes per second.
qDepth Number of requests that are sent to disk and are not completed.
Totals Size (GB) Total size of disks in gigabytes.
Totals Free (GB) Total free space that is left in disks in gigabytes.
Totals Read (MB/s) Total data transfer rate of read data from all disks in megabytes per second.
Totals Write (MB/s) Total data transfer rate of written data to all disks in megabytes per second.

Disk Descriptions (Pressing the D key twice)

The following metrics are shown in this view:
Item Description
Name Disk names.
Size (GB) Size of disks in gigabytes.
Free (GB) Free space that is left in disk in gigabytes.
Disk Paths Number of paths that are defined to the disk.
Disk Adapter Name of disk adapters.
Volume Group Volume group that the disk belongs to.
Disk Description Description of the disk.
Totals Size (GB) Total size of disks in gigabytes.
Totals Free (GB) Total free space that is left in disks in gigabytes.
Totals Read (MB/s) Total data transfer rate of read data from all disks in megabytes per second.
Totals Write (MB/s) Total data transfer rate of written data to all disks in megabytes per second.

Service Times (Pressing the D key three times)

The following metrics are displayed in the view:
Item Description
Disk Name of the disk.
Service (in msecs) Average service time per request in milliseconds.
Wait (in msecs) Average waiting time per request in milliseconds.
ServQ size Average number of requests in service queue.
WaitQ size Average number of requests that is waiting to be accomplished.
ServQ Full Number of times the disk is not accepting any coming requests.
Totals Size (GB) Total size of disks in gigabytes.
Totals Free (GB) Total free space that is left in disks in gigabytes.
Totals Read (MB/s) Total data transfer rate of read data from all disks in megabytes per second.
Totals Write (MB/s) Total data transfer rate of written data to all disks in megabytes per second.

Disk Statistics With Graphs (Pressing the D key four times)

This view displays disk statistics with graphs. To display this view, press the d key. The following metrics are displayed in this view:
Item Description
Name Name of the disk.
Busy Average percentage of busy for the disk.
Read-KB/s Data transfer rate of read data in kilobytes per second.
Write-KB/s Data transfer rate of written data in kilobytes per second.

Memory and Paging Statistics

The view provides information about the memory and paging statistics. To display this view, press the m key. The following metrics are included in this view:
Item Description
%Used Percentage of used space in physical memory and paging space.
%Free Percentage of free space in physical memory and paging space.
MB Used Physical memory and paging space that are used in megabytes.
MB Free Physical memory and paging space that are free in megabytes.
Pages/sec to Paging Space Number of I/O pages that are transferred to or from the paging space per second.
Pages/sec to file system Number of I/O pages that are transferred to or from the file system per second.
Page Scans Number of page scans by clock.
Page Faults Number of page faults.
Page Cycles Number of page replacement cycles.
Page Steals Number of pages steals.
Numperm Number of frames that are used for files (in 4-KB pages).
Process Percentage of real memory that is used by process segments.
System Percentage of real memory that is used by system segments.
Free Percentage of real memory that is free.
Total Percentage of total real memory used.
Min/Maxperm The minperm and maxperm values for page steals.
Min/Maxfree The minfree and maxfree pages free list.
Min/Maxpgahead Minimum and maximum number of page ahead pages.
Total Virtual Total virtual memory.
Accessed Virtual Active virtual memory.
Numclient Number of client frames.
Maxclient Maximum number of client frames.
User Real memory that is used by non-system segments.
Pinned Real memory that is pinned.
The AMS statistics are displayed in the topas_nmon memory panel. To display this view, press the m key. The following metrics are included in this view:
Item Description
Pool AMS pool ID of the pool that the logical partition (LPAR) belongs to.
Weight Weight of the variable memory.
pMem Physical memory currently backing up the logical memory partition (in MB).
hpi Number of hypervisor page-ins.
hpit Time that is spent in hypervisor page-ins (in seconds).
Logical unit information:
Item Description
Size (MB) Total size that is allocated for the logical unit.
Lu Udid Logical unit identifier.

Adapter I/O Statistics View

This view provides the adapter I/O statistics. To display this view, press the a key. The following metrics are displayed in this view:

Item Description
Adapter Name of the adapter.
Busy% Bandwidth use of the adapter. This is the aggregate Busy% of the disks connected to this adapter. The value might exceed 100% if more than one disk is connected to the adapter.
Read-KB/s Data transfer rate of read data in kilobytes per second.
Write-KB/s Data transfer rate of written data in kilobytes per second.
Transfers Number of read and write transfers.
Disks Number of disks.
Adapter-Type Type of the adapter.

Shared Ethernet adapter

This view provides shared Ethernet adapter statistics in a Virtual I/O Server (VIOS). To display this view, press the O key. The following metrics are displayed in this view:
Item Description
Number Serial number.
Name Name of the shared Ethernet adapter.
Recv-KB/s Data transfer rate of received data in kilobytes per second.
Trans-KB/s Data transfer rate of sent data in kilobytes per second.
Packin Number of packets that are received per second in the interval.
Packout Number of packets that are sent per second in the interval.
Insize Average size per second for received packet in the interval.
Outsize Average size per second for outgoing packet in the interval.

Verbose Checks OK/Warn/Danger

This view prints the statistics for processor, memory, and disks. It also prints the status message, such as OK, Warn, or Danger, which is based on the system metrics that exceed the pre-defined threshold values. To display this view, press the v key.

Detailed Page Statistics

This view provides page statistics. To display this view, press the M key.

If you press the M key once, the view contains the statistics in pages. If you press the M key twice, the page statistics are shown in megabytes.

The following metrics are shown in this view:
Item Description
Numframes Number of real memory frames of the page size.
Numfrb Number of pages on free list.
Numclient Number of client frames.
Numcompress Number of frames in compressed segments.
Numperm Number of frames in non-working segments.
Numvpages Number of accessed virtual pages.
Minfree Minimum free list.
Maxfree Maximum free list.
Numpout Number of page-outs.
Numremote Number of remote page-outs.
Numwseguse Number of pages in use for working segments.
Numpseguse Number of pages in use for persistent segments.
Numclseguse Number of pages in use for client segments.
Numwsegpin Number of pages that are pinned for working segments.
Numpsegpin Number of pages that are pinned for persistent segments.
Numclsegpin Number of pages that are pinned for client segments.
numpgsp_pgs Number of allocated page spaces.
numralloc Number of remote allocations.
pfrsvdblks Number of system reserved blocks.
Pfavail Number of pages available for pinning.
Pfpinavail Application level number pages available for pinning.
system_pgs Number of pages on segment control blocks (SCB) that are marked with V_SYSTEM.
nonsys_pgs Number of pages on SCBs not marked with V_SYSTEM.
Numpermio Number of pageouts in non-working storage.
Pgexct Number of page faults.
Pgrclm Number of pages reclaims.
Pageins Number of paged-in pages.
Pageouts Number of paged-out pages.
Pgspgins Number of paged-in pages from page space.
Pgspgouts Number of paged-out pages from page space.
Numsios Number of I/O started.
Numiodone Number of I/O completed.
Zerofills Number of zero-filled pages.
Exfills Number of exec-filled pages.
Scans Number of page scans by clock.
Cycles Number of clock hand cycles.
pgsteals Number of pages steals.

Fibre Channel Adapter Statistics

This view contains information about the Fibre Channel adapter. You can see this view by pressing the caret (-^) key. The following metrics are included in this view:
Item Description
Number Serial number.
Name Name of the Fibre Channel adapter.
Receive-KB/s Data transfer rate of received data in kilobytes per second.
Transmit-KB/s Data transfer rate of sent data in kilobytes per second.
Requests In Number of requests that are received per second in the interval.
Requests Out Number of requests that are sent per second in the interval.
Outsize Average outgoing packet size per second in the interval.

Thread level statistics

This view contains information about thread level statistics. To display this view, press the -i key. The following metrics are included in this view:
Item Description
PID Process ID to which the thread belongs.
TID Top thread ID that utilizes higher CPU. Sorting is based on CPU utilization in descending order.
%CPU Percentage of CPU utilized by the specific thread.
BOUND CPU ID Bounded CPU ID if the thread has been bound to any processor.

Environment Variables

Environment variables NMON_START, NMON_END, NMON_SNAP, and NMON_ONE_IN are used for collecting external data while recording in nmon format.

Item Description
NMONCMD0, NMONCMD1, ..., NMONCMD63 You can monitor only the processes that are set in these variables when these environment variables are set. Alternatively, you can use the -C flag to restrict the commands in the process listing of the nmon command. For example, you can run the nmon -C db2:nmon:topas command.
NMON Contains the set of key strokes corresponding to the initial set of panels to be displayed when the nmon command is started.
NMON_TIMESTAMP You can specify the NMON_TIMESTAMP variable to the following values:
NMON_TIMESTAMP = 0
The recorded lines contain the nmon Tnnnn timestamps at the beginning of the line and work with the nmon data file.
NMON_TIMESTAMP = 1
The lines contains timestamps that have the hours, minute, seconds, day, month, and year. This value can be used if you do not want to merge the data with the nmon file for analysis.
NMON_START External command to be started when the nmon recording begins.
NMON_END External command to be started when the nmon recording ends.
NMON_SNAP External command to be started periodically to record metrics.
NMON_ONE_IN You can specify the NMON_ONE_IN variable to the following values:
NMON_ONE_IN=1
Runs the snap command every time the recording is done.
NMON_ONE_IN=n
Runs the snap command after the number of recordings that are specified by the n parameter is done.

Examples

  1. To generate the nmon recording in the current directory for two hours, capturing data every 30 seconds, enter the following command:
    nmon -f -s 30 -c 240
  2. To display the memory and processor statistics immediately after the nmon command is started, do the following steps:
    1. Enter the following command:
      export NMON=mc
    2. Run the nmon command.
  3. To run the nmon command for 20 seconds with the screen that is refreshed at 10 seconds, enter the following command:
    nmon -c 10 -s 2
  4. To run nmon in black and white mode, enter the following command:
    nmon -b
  5. To view the process information, do the following steps:
    1. Run the nmon command.
    2. Press the t key.
  6. To view the list of views that nmon command provides, press the key h.
  7. The following sample explains the steps to collect external data. In the sample, the mystart file, the mysnap file, and the myend file are executable and are in the path that the $PATH defines.
    1. Set the environment variables as indicated in the following example:
      $export NMON_TIMESTAMP=0
      $export NMON_START="mystart"
      $export NMON_SNAP="mysnap"
      $export NMON_END="myend"
      $export NMON_ONE_IN=1
      In the previous example, the value of one is the default value for the NMON_ONE_IN environment variable. It generates one set of external recorded data for every snapshot of nmon recording.
    2. Modify the content of the mystart file as the following:
      ps -ef >start_ps.xt
      echo "PROCCOUNT,Process Count, Procs" >ps.csv
    3. Modify the content of the mysnap file as the following:
      echo PROCCOUNT,$1,`ps -ef | wc -l` >>ps.csv
    4. Modify the content of the myend file as the following:
      echo PROCCOUNT,$1,`ps -ef | wc -l` >>ps.csv
    5. Run the nmon command as follows:
      nmon -f -s 2 -c 10
      The recording finishes in 20 seconds.
    The output of the ps.csv file is similar to the following sample:
    PROCCOUNT,Process Count, Procs
    PROCCOUNT,T0001, 43
    PROCCOUNT,T0002, 43
    PROCCOUNT,T0003, 43
    PROCCOUNT,T0004, 43
    PROCCOUNT,T0005, 43
    PROCCOUNT,T0006, 43
    PROCCOUNT,T0007, 43
    PROCCOUNT,T0008, 43
    PROCCOUNT,T0009, 44
    PROCCOUNT,T0010, 44
    PROCCOUNT,T0010, 44
    To concatenate the generated nmon file with the ps.csv file that is generated by external recording, enter the following command:
    cat  filename.nmon ps.csv > c.csv
    To get the graph, open the c.csv file in nmon analyzer.
  8. To view the hdisk details, enter the nmon command with -k flag:
    nmon -k hdisk1,hdisk2
    The previous command shows the disk details for hdisk1 and hdisk2. For hdiskpower devices, enter the following command:
    nmon -k hdiskpower or
    nmon -k power
    Note: The nmon -k hdisk matches all the hdisk devices on the LPAR and does not match the hdiskpower devices.
    All hdiskpower devices display as power in interactive and recording modes. For example, nmon -k hdiskpower1 matches the device hdiskpower1 and nmon -k hdiskpower matches all hdiskpower devices on the LPAR.
    Note: The output of the lsconf and lspv commands in the nmon recording file is not affected by the changes to the nmon-k command.

Location

/usr/bin/nmon

/usr/bin/topasrec