System Administration Guide: Advanced Administration

Monitoring System Activities (sar)

Use the sar command to do the following:

For a detailed description of this command, see sar(1).

How to Check File Access (sar -a)

Display file access operation statistics with the sar -a command.


$ sar -a
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00  iget/s namei/s dirbk/s
01:00:00       0       0       0
02:00:02       0       0       0
03:00:00       0       1       0
04:00:00       0       0       0
05:00:01       0       0       0
06:00:00       0       0       0

Average        0       1       0

The following table describes the operating system routines that are reported by the sar -a command.

Table 24–7 Output from the sar -a Command

Field Name 

Description 

iget/s

The number of requests made for inodes that were not in the directory name look-up cache (DNLC). 

namei/s

The number of file system path searches per second. If namei does not find a directory name in the DNLC, it calls iget to get the inode for either a file or directory. Hence, most igets are the result of DNLC misses.

dirbk/s

The number of directory block reads issued per second. 

The larger the reported values, the more time the kernel is spending to access user files. The amount of time reflects how heavily programs and applications are using the file systems. The -a option is helpful for viewing how disk-dependent an application is.

How to Check Buffer Activity (sar -b)

Display buffer activity statistics with the sar -b command.

The buffer is used to cache metadata, which includes inodes, cylinder group blocks, and indirect blocks.


$ sar -b
00:00:00 bread/s lread/s %rcache bwrit/s lwrit/s %wcache pread/s pwrit/s
01:00:00       0       0     100       0       0      55       0       0

The following table describes the buffer activities that are displayed by the -b option.

Table 24–8 Output From the sar -b Command

Field Name 

Description 

bread/s

Average number of reads per second that are submitted to the buffer cache from the disk 

lread/s

Average number of logical reads per second from the buffer cache 

%rcache

Fraction of logical reads that are found in the buffer cache (100% minus the ratio of bread/s to lread/s)

bwrit/s

Average number of physical blocks (512 blocks) that are written from the buffer cache to disk, per second 

lwrit/s

Average number of logical writes to the buffer cache, per second 

%wcache

Fraction of logical writes that are found in the buffer cache (100% minus the ratio of bwrit/s to lwrit/s)

pread/s

Average number of physical reads, per second that use character device interfaces 

pwrit/s

Average number of physical write requests, per second that use character device interfaces 

The most important entries are the cache hit ratios %rcache and %wcache, which measure the effectiveness of system buffering. If %rcache falls below 90 percent, or if %wcache falls below 65 percent, it might be possible to improve performance by increasing the buffer space.

Example—Checking Buffer Activity

The following abbreviated example of sar -b output shows that the %rcache and %wcache buffers are not causing any slowdowns. All the data is within acceptable limits.


$ sar -b
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00 bread/s lread/s %rcache bwrit/s lwrit/s %wcache pread/s pwrit/s
01:00:00       0       0     100       0       0      55       0       0
02:00:02       0       0     100       0       0      55       0       0
03:00:00       0       0     100       0       0      72       0       0
04:00:00       0       0     100       0       0      56       0       0
05:00:01       0       0     100       0       0      55       0       0
06:00:00       0       0     100       0       0      55       0       0

Average        0       0      94       0       0      64       0       0

How to Check System Call Statistics (sar -c)

Display system call statistics by using the sar -c command.


$ sar -c
00:00:00 scall/s sread/s swrit/s  fork/s  exec/s rchar/s wchar/s
01:00:00      38       2       2    0.00    0.00     149     120

The following table describes the system call categories that are reported by the -c option. Typically, reads and writes account for about half of the total system calls, although the percentage varies greatly with the activities that are being performed by the system.

Table 24–9 Output From the sar -c Command

Field Name 

Description 

scall/s

All types of system calls per second (generally about 30 per second on a system with 4 to 6 users). 

sread/s

read system calls per second.

swrit/s

write system calls per second.

fork/s

fork system calls per second (about 0.5 per second on a system with 4 to 6 users). This number will increase if shell scripts are running.

exec/s

exec system calls per second. If exec/s divided by fork/s is greater than three, look for inefficient PATH variables.

rchar/s

Characters (bytes) transferred by read system calls per second.

wchar/s

Characters (bytes) transferred by write system calls per second.

Example—Checking System Call Statistics

The following abbreviated example shows output from the sar -c command.


$ sar -c
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00 scall/s sread/s swrit/s  fork/s  exec/s rchar/s wchar/s
01:00:00      38       2       2    0.00    0.00     149     120
02:00:02      38       2       2    0.00    0.00     149     120
03:00:00      42       2       2    0.05    0.05     218     147
04:00:00      39       2       2    0.01    0.00     155     123
05:00:01      38       2       2    0.00    0.00     150     120
06:00:00      38       2       2    0.01    0.00     149     120

Average       50       4       3    0.02    0.02     532     238

How to Check Disk Activity (sar -d)

Display disk activity statistics with the sar -d command.


$ sar -d
00:00:00   device        %busy   avque   r+w/s  blks/s  avwait  avserv

01:00:00   fd0               0     0.0       0       0     0.0     0.0

The following table describes the disk device activities that are reported by the -d option.

Table 24–10 Output From the sar -d Command

Field Name 

Description 

device

Name of the disk device that is being monitored 

%busy

Percentage of time the device spent servicing a transfer request 

avque

The sum of the average wait time plus the average service time 

r+w/s

Number of read and write transfers to the device, per second 

blks/s

Number of 512-byte blocks that are transferred to the device, per second 

avwait

Average time, in milliseconds, that transfer requests wait idly in the queue (measured only when the queue is occupied) 

avserv

Average time, in milliseconds, for a transfer request to be completed by the device (for disks, this value includes seek, rotational latency, and data transfer times) 

Note that queue lengths and wait times are measured when there is something in the queue. If %busy is small, large queues and service times probably represent the periodic efforts by the system to ensure that altered blocks are promptly written to the disk.

Examples—Checking Disk Activity

This abbreviated example illustrates the sar -d output.


$ sar -d
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00   device        %busy   avque   r+w/s  blks/s  avwait  avserv

01:00:00   fd0               0     0.0       0       0     0.0     0.0
           nfs1              0     0.0       0       0     0.0     0.0
           sd0               0     0.0       0       0     0.0    39.6
           sd0,a             0     0.0       0       0     0.0    39.6
           sd0,b             0     0.0       0       0     0.0     0.0
           sd0,c             0     0.0       0       0     0.0     0.0
           sd0,f             0     0.0       0       0     0.0     0.0
           sd0,g             0     0.0       0       0     0.0     0.0
           sd0,h             0     0.0       0       0     0.0     0.0
           sd6               0     0.0       0       0     0.0     0.0

How to Check Page-Out and Memory (sar -g)

Use the sar -g command to display page-out and memory freeing activities (in averages).


$ sar -g
00:00:00  pgout/s ppgout/s pgfree/s pgscan/s %ufs_ipf
01:00:00     0.00     0.00     0.00     0.00     0.00

The output displayed by the sar -g command is a good indicator of whether more memory may be needed. Use the ps -elf command to show the number of cycles that are used by the page daemon. A high number of cycles, combined with high values for pgfree/s and pgscan/s, indicates a memory shortage.

The sar -g command also shows whether inodes are being recycled too quickly and causing a loss of reusable pages.

The following table describes the output from the -g option.

Table 24–11 Output From the sar -g Command

Field Name 

Description 

pgout/s

The number of page-out requests per second. 

ppgout/s

The actual number of pages that are paged-out, per second. A single page-out request might involve paging-out multiple pages. 

pgfree/s

The number of pages, per second, that are placed on the free list. 

pgscan/s

The number of pages, per second, that are scanned by the page daemon. If this value is high, the page daemon is spending a lot of time checking for free memory. This situation implies that more memory might be needed.  

%ufs_ipf

The percentage of ufs inodes taken off the free list by iget that had reusable pages associated with them. These pages are flushed and cannot be reclaimed by processes. Thus, this field represents the percentage of igets with page flushes. A high value indicates that the free list of inodes is page-bound, and the number of ufs inodes might need to be increased.

Example—Checking Page-Out and Memory

The following abbreviated example shows output from the sar -g command.


$ sar -g
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00  pgout/s ppgout/s pgfree/s pgscan/s %ufs_ipf
01:00:00     0.00     0.00     0.00     0.00     0.00
02:00:02     0.00     0.00     0.00     0.00     0.00
03:00:00     0.00     0.01     0.01     0.00     0.00
04:00:00     0.00     0.00     0.00     0.00     0.00
05:00:01     0.00     0.00     0.00     0.00     0.00
06:00:00     0.00     0.00     0.00     0.00     0.00

Average      0.01     0.12     0.21     0.66     0.00

How to Check Kernel Memory Allocation (sar -k)

Use the sar -k command to report on the following activities of the Kernel Memory Allocator (KMA).

The KMA allows a kernel subsystem to allocate and free memory as needed. Rather than statically allocating the maximum amount of memory it is expected to require under peak load, the KMA divides requests for memory into three categories: small (less than 256 bytes), large (512 bytes to 4 Kbytes), and oversized (greater than 4 Kbytes). The KMA keeps two pools of memory to satisfy small and large requests. The oversized requests are satisfied by allocating memory from the system page allocator.

If you are investigating a system that is being used to write drivers or STREAMS that use KMA resources, then the sar -k command will likely prove useful. Otherwise, you will probably not need the information it provides. Any driver or module that uses KMA resources, but does not specifically return the resources before it exits, can create a memory leak. A memory leak causes the amount of memory that is allocated by KMA to increase over time. Thus, if the alloc fields of the sar -k command increase steadily over time, there might be a memory leak. Another indication of a memory leak is failed requests. If this problem occurs, a memory leak has probably caused KMA to be unable to reserve and allocate memory.

If it appears that a memory leak has occurred, you should check any drivers or STREAMS that might have requested memory from KMA and not returned it.


$ sar -k
00:00:00 sml_mem   alloc  fail  lg_mem   alloc   fail  ovsz_alloc  fail
01:00:00 2523136 1866512     0 18939904 14762364    0      360448     0
02:00:02 2523136 1861724     0 18939904 14778748    0      360448     0

The following table describes the output from the -k option.

Table 24–12 Output From the sar -k Command

Field Name 

Description 

sml_mem

The amount of memory, in bytes, that the KMA has available in the small memory request pool (a small request is less than 256 bytes). 

alloc

The amount of memory, in bytes, that the KMA has allocated from its small memory request pool to small memory requests. 

fail

The number of requests for small amounts of memory that failed. 

lg_mem

The amount of memory, in bytes, that the KMA has available in the large memory request pool (a large request is from 512 bytes to 4 Kbytes). 

alloc

The amount of memory, in bytes, that the KMA has allocated from its large memory request pool to large memory requests. 

fail

The number of failed requests for large amounts of memory 

ovsz_alloc

The amount of memory that is allocated for oversized requests (those requests that are greater than 4 Kbytes). These requests are satisfied by the page allocator. Thus, there is no pool. 

fail

The number of failed requests for oversized amounts of memory. 

Example—Checking Kernel Memory Allocation (sar)

The following is an abbreviated example of sar -k output.


$ sar -k
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00 sml_mem   alloc  fail  lg_mem   alloc  fail  ovsz_alloc  fail
01:00:00 2523136 1866512     0 18939904 14762364     0      360448     0
02:00:02 2523136 1861724     0 18939904 14778748     0      360448     0
03:00:00 2523136 1865664     0 18939904 14745884     0      360448     0
04:00:00 2523136 1867692     0 18939904 14746616     0      360448     0
05:00:01 2523136 1867208     0 18939904 14763700     0      360448     0
06:00:00 2523136 1867772     0 18939904 14779444     0      360448     0

Average  2724096 1791806     0 20089344 15434591     0      360448     0

How to Check Interprocess Communication (sar -m)

Use the sar -m command to report interprocess communication activities.


$ sar -m 
00:00:00   msg/s  sema/s
01:00:00    0.00    0.00

These figures will usually be zero (0.00), unless you are running applications that use messages or semaphores.

The following table describes the output from the -m option.

Table 24–13 Output From the sar -m Command

Field Name 

Description 

msg/s

The number of message operations (sends and receives) per second 

sema/s

The number of semaphore operations per second 

Example—Checking Interprocess Communication

The following abbreviated example shows output from the sar -m command.


$ sar -m
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00   msg/s  sema/s
01:00:00    0.00    0.00
02:00:02    0.00    0.00
03:00:00    0.00    0.00
04:00:00    0.00    0.00
05:00:01    0.00    0.00
06:00:00    0.00    0.00

Average     0.00    0.00

How to Check Page-In Activity (sar -p)

Use the sar -p command to report page-in activity which includes protection and translation faults.


$ sar -p
00:00:00  atch/s  pgin/s ppgin/s  pflt/s  vflt/s slock/s
01:00:00    0.07    0.00    0.00    0.21    0.39    0.00

The following table describes the reported statistics from the -p option.

Table 24–14 Output From the sar -p Command

Field Name 

Description 

atch/s

The number of page faults, per second, that are satisfied by reclaiming a page currently in memory (attaches per second). Instances include reclaiming an invalid page from the free list and sharing a page of text that is currently being used by another process (for example, two or more processes that are accessing the same program text). 

pgin/s

The number of times, per second, that file systems receive page-in requests. 

ppgin/s

The number of pages paged in, per second. A single page-in request, such as a soft-lock request (see slock/s), or a large block size, might involve paging-in multiple pages.

pflt/s

The number of page faults from protection errors. Instances of protection faults are illegal access to a page and “copy-on-writes.” Generally, this number consists primarily of “copy-on-writes.” 

vflt/s

The number of address translation page faults, per second. These faults are known as validity faults, and occur when a valid process table entry does not exist for a given virtual address. 

slock/s

The number of faults, per second, caused by software lock requests that require physical I/O. An example of the occurrence of a soft-lock request is the transfer of data from a disk to memory. The system locks the page that is to receive the data, so that it cannot be claimed and used by another process.  

Example—Checking Page-In Activity

The following abbreviated example shows output from the sar -p command.


$ sar -p
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00  atch/s  pgin/s ppgin/s  pflt/s  vflt/s slock/s
01:00:00    0.07    0.00    0.00    0.21    0.39    0.00
02:00:02    0.07    0.00    0.00    0.21    0.39    0.00
03:00:00    0.32    0.00    0.00    1.10    2.48    0.00
04:00:00    0.09    0.00    0.00    0.32    0.57    0.00
05:00:01    0.07    0.00    0.00    0.21    0.39    0.00
06:00:00    0.07    0.00    0.00    0.21    0.39    0.00

Average     0.26    0.20    0.30    0.92    1.78    0.00

How to Check Queue Activity (sar -q)

Use the sar -q command to report the average queue length while the queue is occupied, and the percentage of time that the queue is occupied.


$ sar -q
00:00:00 runq-sz %runocc swpq-sz %swpocc

Note –

The number of LWPs swapped out might be greater than zero even if the system has an abundance of free memory. This situation happens when a sleeping LWP is swapped out and has not been awakened (for example, a process or LWP is sleeping, waiting for keyboard or mouse input).


The following table describes the output from the -q option.

Table 24–15 Output From the sar -q Command

Field Name 

Description 

runq-sz

The number of kernel threads in memory that are waiting for a CPU to run. Typically, this value should be less than 2. Consistently higher values mean that the system might be CPU-bound. 

%runocc

The percentage of time that the dispatch queues are occupied. 

swpq-sz

The average number of swapped out LWPs. 

%swpocc

The percentage of time LWPs are swapped out. 

Example—Checking Queue Activity

The following abbreviated example shows output from the sar -q command. If %runocc is high (greater than 90 percent) and runq-sz is greater than 2, the CPU is heavily loaded and response is degraded. In this case, additional CPU capacity might be required to obtain acceptable system response.


$ sar -q
SunOS venus 5.9 Generic sun4u    06/24/2001

08:45:18 runq-sz %runocc swpq-sz %swpocc
08:45:18        unix restarts
09:00:00     1.0       0     0.0       0
09:20:00     0.0       0     0.0       0
09:40:00     0.0       0     0.0       0

Average      1.0       0     0.0       0

How to Check Unused Memory (sar -r)

Use the sar -r command to report the number of memory pages and swap-file disk blocks that are currently unused.


$ sar -r
00:00:00 freemem freeswap
01:00:00    2135   401922

The following table describes the output from the -r option.

Table 24–16 Output From the sar -r Command

Field Name 

Description 

freemem

The average number of memory pages that are available to user processes over the intervals sampled by the command. Page size is machine-dependent. 

freeswap

The number of 512-byte disk blocks that are available for page swapping. 

Example—Checking Unused Memory

The following example shows output from the sar -r command.


$ sar -r
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00 freemem freeswap
01:00:00    2135   401922
02:00:02    2137   401949
03:00:00    2137   402006
04:00:00    2139   401923
05:00:01    2138   402033
06:00:00    2137   401919

Average     2500   399914

How to Check CPU Utilization (sar -u)

Use the sar -u command to display CPU utilization statistics.


$ sar -u
00:00:00    %usr    %sys    %wio   %idle
01:00:00       0       0       0     100

The sar command without any options is equivalent to sar -u. At any given moment, the processor is either busy or idle. When busy, the processor is in either user mode or system mode. When idle, the processor is either waiting for I/O completion or “sitting still” with no work to do.

The following table describes output from the -u option.

Table 24–17 Output From the sar -u Command

Field Name 

Description 

%usr

Lists the percentage of time that the processor is in user mode 

%sys

Lists the percentage of time that the processor is in system mode 

%wio

Lists the percentage of time that the processor is idle and waiting for I/O completion 

%idle

Lists the percentage of time that the processor is idle and not waiting for I/O 

A high %wio generally means that a disk slowdown has occurred.

Example—Checking CPU Utilization

The following example shows output from the sar -u command.


$ sar -u
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00    %usr    %sys    %wio   %idle
01:00:00       0       0       0     100
02:00:02       0       0       0     100
03:00:00       0       0       0     100
04:00:00       0       0       0     100
05:00:01       0       0       0     100
06:00:00       0       0       0     100
07:00:00       0       0       0     100
08:00:01       0       0       0     100
08:20:00       0       0       0     100
08:40:00       0       0       0     100
09:00:00       0       0       0     100
09:20:00       0       0       0     100
09:40:00       0       0       0     100
10:00:00       0       0       0     100
10:20:00       0       0       0     100
10:40:01       0       0       0     100
11:00:00       5       2      10      82

Average        0       0       0     100

How to Check System Table Status (sar -v)

Use the sar -v command to report the status of the process table, inode table, file table, and shared memory record table.


$ sar -v
00:00:00  proc-sz    ov  inod-sz    ov  file-sz    ov   lock-sz
01:00:00   43/922     0 2984/4236    0  322/322     0    0/0   

Output from the -v option is described in the following table.

Table 24–18 Output From the sar -v Command

Field Name 

Description 

proc-sz

The number of process entries (proc structures) that are currently being used, or allocated in the kernel.

inod-sz

The total number of inodes in memory verses the maximum number of inodes that are allocated in the kernel. This number is not a strict high water mark; it can overflow. 

file-sz

The size of the open system file table. The sz is given as 0, since space is allocated dynamically for the file table.

ov

The number of shared memory record table entries that are currently being used or allocated in the kernel. The sz is given as 0 because space is allocated dynamically for the shared memory record table.

lock-sz

The number of shared memory record table entries that are currently being used or allocated in the kernel. The sz is given as 0 because space is allocated dynamically for the shared memory record table.

Example—Checking System Table Status

The following abbreviated example shows output from the sar -v command. This example shows that all tables are large enough to have no overflows. These tables are all dynamically allocated based on the amount of physical memory.


$ sar -v
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00  proc-sz    ov  inod-sz    ov  file-sz    ov   lock-sz
01:00:00   43/922     0 2984/4236    0  322/322     0    0/0   
02:00:02   43/922     0 2984/4236    0  322/322     0    0/0   
03:00:00   43/922     0 2986/4236    0  323/323     0    0/0   
04:00:00   43/922     0 2987/4236    0  322/322     0    0/0   
05:00:01   43/922     0 2987/4236    0  322/322     0    0/0   
06:00:00   43/922     0 2987/4236    0  322/322     0    0/0   

How to Check Swapping Activity (sar -w)

Use the sar -w command to report swapping and switching activity.


$ sar -w
00:00:00 swpin/s bswin/s swpot/s bswot/s pswch/s
01:00:00    0.00     0.0    0.00     0.0      22

The following table describes target values and observations.

Table 24–19 Output From the sar -w Command

Field Name 

Description 

swpin/s

The number of LWP transfers into memory per second. 

bswin/s

The average number of processes that are swapped out of memory per second. If the number is greater than 1, you might need to increase memory. 

swpot/s

The average number of processes that are swapped out of memory per second. If the number is greater than 1, you might need to increase memory. 

bswot/s

The number of blocks that are transferred for swap-outs per second. 

pswch/s

The number of kernel thread switches, per second. 


Note –

All process swap-ins include process initialization.


Example—Checking Swap Activity

The following example shows output from the sar -w command.


$ sar -w
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00 swpin/s bswin/s swpot/s bswot/s pswch/s
01:00:00    0.00     0.0    0.00     0.0      22
02:00:02    0.00     0.0    0.00     0.0      22
03:00:00    0.00     0.0    0.00     0.0      22
04:00:00    0.00     0.0    0.00     0.0      22
05:00:01    0.00     0.0    0.00     0.0      22
06:00:00    0.00     0.0    0.00     0.0      22
07:00:00    0.00     0.0    0.00     0.0      22
08:00:01    0.00     0.0    0.00     0.0      22
08:20:00    0.00     0.0    0.00     0.0      22
08:40:00    0.00     0.0    0.00     0.0      22
09:00:00    0.00     0.0    0.00     0.0      22
09:20:00    0.00     0.0    0.00     0.0      22
09:40:00    0.00     0.0    0.00     0.0      22
10:00:00    0.00     0.0    0.00     0.0      22
10:20:00    0.00     0.0    0.00     0.0      22
10:40:01    0.00     0.0    0.00     0.0      23
11:00:00    0.00     0.0    0.00     0.0     144

Average     0.00     0.0    0.00     0.0      24

How to Check Terminal Activity (sar -y)

Use the sar -y command to monitor terminal device activities.


$ sar -y
00:00:00 rawch/s canch/s outch/s rcvin/s xmtin/s mdmin/s
01:00:00       0       0       0       0       0       0

If you have a lot of terminal I/O, you can use this report to determine if there are any bad lines. The activities recorded are defined in the following table.

Table 24–20 Output From the sar -y Command

Field Name 

Description 

rawch/s

Input characters (raw queue), per second 

canch/s

Input characters that are processed by canon (canonical queue), per second 

outch/s

Output characters (output queue) per second 

rcvin/s

Receiver hardware interrupts per second 

xmtin/s

Transmitter hardware interrupts per second 

mdmin/s

Modem interrupts per second 

The number of modem interrupts per second (mdmin/s) should be close to zero. The receive and transmit interrupts per second (xmtin/s and rcvin/s) should be less than or equal to the number of incoming or outgoing characters, respectively. If this is not the case, check for bad lines.

Example—Checking Terminal Activity

The following abbreviated example shows output from the sar -y command.


$ sar -y
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00 rawch/s canch/s outch/s rcvin/s xmtin/s mdmin/s
01:00:00       0       0       0       0       0       0
02:00:02       0       0       0       0       0       0
03:00:00       0       0       0       0       0       0
04:00:00       0       0       0       0       0       0
05:00:01       0       0       0       0       0       0
06:00:00       0       0       0       0       0       0
07:00:00       0       0       0       0       0       0
08:00:01       0       0       0       0       0       0
08:20:00       0       0       0       0       0       0
08:40:00       0       0       0       0       0       0
09:00:00       0       0       0       0       0       0
09:20:00       0       0       0       0       0       0
09:40:00       0       0       0       0       0       0
10:00:00       0       0       0       0       0       0
10:20:00       0       0       0       0       0       0
10:40:01       0       0      20       0       0       0

Average        0       0       3       0       0       0

How to Check Overall System Performance (sar -A)

Use the sar -A command to display statistics from all options to provide a view of overall system performance.

This command provides a more global perspective. If data from more than a single time segment is shown, the report includes averages.