sar Man page

SAR(1) Linux User’s Manual SAR(1)

NAME

sar – Collect, report, or save system activity information.

SYNOPSIS

sar [ -A ] [ -B ] [ -b ] [ -C ] [ -D ] [ -d ] [ -F [ MOUNT ] ] [ -H ] [
-h ] [ -p ] [ -q ] [ -R ] [ -r [ ALL ] ] [ -S ] [ -t ] [ -u [ ALL ] ] [
-V ] [ -v ] [ -W ] [ -w ] [ -y ] [ –sadc ] [ -I { int [,…] | SUM |
ALL | XALL } ] [ -P { cpu [,…] | ALL } ] [ -m { keyword [,…] | ALL
} ] [ -n { keyword [,…] | ALL } ] [ -j { ID | LABEL | PATH | UUID |
… } ] [ -f [ filename ] | -o [ filename ] | -[0-9]+ ] [ -i interval ] [ -s [ hh:mm[:ss] ] ] [ -e [ hh:mm[:ss] ] ] [ interval [ count ] ]

DESCRIPTION

The sar command writes to standard output the contents of selected
cumulative activity counters in the operating system. The accounting
system, based on the values in the count and interval parameters,
writes information the specified number of times spaced at the speci‐
fied intervals in seconds. If the interval parameter is set to zero,
the sar command displays the average statistics for the time since the
system was started. If the interval parameter is specified without the
count parameter, then reports are generated continuously. The col‐
lected data can also be saved in the file specified by the -o filename
flag, in addition to being displayed onto the screen. If filename is
omitted, sar uses the standard system activity daily data file (see
below). By default all the data available from the kernel are saved in
the data file.

The sar command extracts and writes to standard output records previ‐
ously saved in a file. This file can be either the one specified by the
-f flag or, by default, the standard system activity daily data file.
It is also possible to enter -1, -2 etc. as an argument to sar to dis‐
play data of that days ago. For example, -1 will point at the standard
system activity file of yesterday.

Standard system activity daily data files are named saDD or saYYYYMMDD,
where YYYY stands for the current year, MM for the current month and DD
for the current day. They are the default files used by sar only when
no filename has been explicitly specified. When used to write data to
files (with its option -o), sar will use saYYYYMMDD if option -D has
also been specified, else it will use saDD. When used to display the
records previously saved in a file, sar will look for the most recent
of saDD and saYYYYMMDD, and use it.

Standard system activity daily data files are located in the
/var/log/sysstat directory by default. Yet it is possible to specify an
alternate location for them: If a directory (instead of a plain file)
is used with options -f or -o then it will be considered as the direc‐
tory containing the data files.

Without the -P flag, the sar command reports system-wide (global among
all processors) statistics, which are calculated as averages for values
expressed as percentages, and as sums otherwise. If the -P flag is
given, the sar command reports activity which relates to the specified
processor or processors. If -P ALL is given, the sar command reports
statistics for each individual processor and global statistics among
all processors.

You can select information about specific system activities using
flags. Not specifying any flags selects only CPU activity. Specifying
the -A flag selects all possible activities.

The default version of the sar command (CPU utilization report) might
be one of the first facilities the user runs to begin system activity
investigation, because it monitors major system resources. If CPU uti‐
lization is near 100 percent (user + nice + system), the workload sam‐
pled is CPU-bound.

If multiple samples and multiple reports are desired, it is convenient
to specify an output file for the sar command. Run the sar command as
a background process. The syntax for this is:

sar -o datafile interval count >/dev/null 2>&1 &

All data are captured in binary form and saved to a file (datafile).
The data can then be selectively displayed with the sar command using
the -f option. Set the interval and count parameters to select count
records at interval second intervals. If the count parameter is not
set, all the records saved in the file will be selected. Collection of
data in this manner is useful to characterize system usage over a
period of time and determine peak usage hours.

Note: The sar command only reports on local activities.

OPTIONS

-A This is equivalent to specifying -bBdFHqRSuvwWy -I SUM -I XALL
-m ALL -n ALL -r ALL -u ALL -P ALL.

-B Report paging statistics. The following values are displayed:

pgpgin/s
Total number of kilobytes the system paged in from disk
per second.

pgpgout/s
Total number of kilobytes the system paged out to disk
per second.

fault/s
Number of page faults (major + minor) made by the system
per second. This is not a count of page faults that gen‐
erate I/O, because some page faults can be resolved with‐
out I/O.

majflt/s
Number of major faults the system has made per second,
those which have required loading a memory page from
disk.

pgfree/s
Number of pages placed on the free list by the system per
second.

pgscank/s
Number of pages scanned by the kswapd daemon per second.

pgscand/s
Number of pages scanned directly per second.

pgsteal/s
Number of pages the system has reclaimed from cache
(pagecache and swapcache) per second to satisfy its mem‐
ory demands.

%vmeff
Calculated as pgsteal / pgscan, this is a metric of the
efficiency of page reclaim. If it is near 100% then
almost every page coming off the tail of the inactive
list is being reaped. If it gets too low (e.g. less than
30%) then the virtual memory is having some difficulty.
This field is displayed as zero if no pages have been
scanned during the interval of time.

-b Report I/O and transfer rate statistics. The following values
are displayed:

tps
Total number of transfers per second that were issued to
physical devices. A transfer is an I/O request to a
physical device. Multiple logical requests can be com‐
bined into a single I/O request to the device. A trans‐
fer is of indeterminate size.

rtps
Total number of read requests per second issued to physi‐
cal devices.

wtps
Total number of write requests per second issued to phys‐
ical devices.

bread/s
Total amount of data read from the devices in blocks per
second. Blocks are equivalent to sectors and therefore
have a size of 512 bytes.

bwrtn/s
Total amount of data written to devices in blocks per
second.

-C When reading data from a file, tell sar to display comments that
have been inserted by sadc.

-D Use saYYYYMMDD instead of saDD as the standard system activity
daily data file name. This option works only when used in con‐
junction with option -o to save data to file.

-d Report activity for each block device. When data are displayed,
the device specification devM-n is generally used (DEV column).
M is the major number of the device and n its minor number.
Device names may also be pretty-printed if option -p is used or
persistent device names can be printed if option -j is used (see
below). Note that disk activity depends on sadc options -S DISK
and -S XDISK to be collected. The following values are dis‐
played:

tps
Indicate the number of transfers per second that were
issued to the device. Multiple logical requests can be
combined into a single I/O request to the device. A
transfer is of indeterminate size.

rd_sec/s
Number of sectors read from the device. The size of a
sector is 512 bytes.

wr_sec/s
Number of sectors written to the device. The size of a
sector is 512 bytes.

avgrq-sz
The average size (in sectors) of the requests that were
issued to the device.

avgqu-sz
The average queue length of the requests that were issued
to the device.

await
The average time (in milliseconds) for I/O requests
issued to the device to be served. This includes the time
spent by the requests in queue and the time spent servic‐
ing them.

svctm
The average service time (in milliseconds) for I/O
requests that were issued to the device. Warning! Do not
trust this field any more. This field will be removed in
a future sysstat version.

%util
Percentage of elapsed time during which I/O requests were
issued to the device (bandwidth utilization for the
device). Device saturation occurs when this value is
close to 100% for devices serving requests serially. But
for devices serving requests in parallel, such as RAID
arrays and modern SSDs, this number does not reflect
their performance limits.

-e [ hh:mm[:ss] ] Set the ending time of the report. The default ending time is
18:00:00. Hours must be given in 24-hour format. This option
can be used when data are read from or written to a file
(options -f or -o).

-F [ MOUNT ] Display statistics for currently mounted filesystems.
Pseudo-filesystems are ignored. At the end of the report, sar
will display a summary of all those filesystems. Use of the
MOUNT parameter keyword indicates that mountpoint will be
reported instead of filesystem device. Note that filesystems
statistics depend on sadc option -S XDISK to be collected.

The following values are displayed:

MBfsfree
Total amount a free space in megabytes (including space
available only to privileged user).

MBfsused
Total amount of space used in megabytes.

%fsused
Percentage of filesystem space used, as seen by a privi‐
leged user.

%ufsused
Percentage of filesystem space used, as seen by an
unprivileged user.

Ifree
Total number of free file nodes in filesystem.

Iused
Total number of file nodes used in filesystem.

%Iused
Percentage of file nodes used in filesystem.

-f [ filename ] Extract records from filename (created by the -o filename flag).
The default value of the filename parameter is the current stan‐
dard system activity daily data file. If filename is a direc‐
tory instead of a plain file then it is considered as the direc‐
tory where the standard system activity daily data files are
located. The -f option is exclusive of the -o option.

-H Report hugepages utilization statistics. The following values
are displayed:

kbhugfree
Amount of hugepages memory in kilobytes that is not yet
allocated.

kbhugused
Amount of hugepages memory in kilobytes that has been
allocated.

%hugused
Percentage of total hugepages memory that has been allo‐
cated.

-h Display a short help message then exit.

-I { int [,…] | SUM | ALL | XALL }
Report statistics for a given interrupt. int is the interrupt
number. Specifying multiple -I int parameters on the command
line will look at multiple independent interrupts. The SUM key‐
word indicates that the total number of interrupts received per
second is to be displayed. The ALL keyword indicates that sta‐
tistics from the first 16 interrupts are to be reported, whereas
the XALL keyword indicates that statistics from all interrupts,
including potential APIC interrupt sources, are to be reported.
Note that interrupt statistics depend on sadc option “-S INT” to
be collected.

-i interval
Select data records at seconds as close as possible to the num‐
ber specified by the interval parameter.

-j { ID | LABEL | PATH | UUID | … }
Display persistent device names. Use this option in conjunction
with option -d. Options ID, LABEL, etc. specify the type of the
persistent name. These options are not limited, only prerequi‐
site is that directory with required persistent names is present
in /dev/disk. If persistent name is not found for the device,
the device name is pretty-printed (see option -p below).

-m { keyword [,…] | ALL }
Report power management statistics. Note that these statistics
depend on sadc’s option “-S POWER” to be collected.

Possible keywords are CPU, FAN, FREQ, IN, TEMP and USB.

With the CPU keyword, statistics about CPU are reported. The
following value is displayed:

MHz
Instantaneous CPU clock frequency in MHz.

With the FAN keyword, statistics about fans speed are reported.
The following values are displayed:

rpm
Fan speed expressed in revolutions per minute.

drpm
This field is calculated as the difference between cur‐
rent fan speed (rpm) and its low limit (fan_min).

DEVICE
Sensor device name.

With the FREQ keyword, statistics about CPU clock frequency are
reported. The following value is displayed:

wghMHz
Weighted average CPU clock frequency in MHz. Note that
the cpufreq-stats driver must be compiled in the kernel
for this option to work.

With the IN keyword, statistics about voltage inputs are
reported. The following values are displayed:

inV
Voltage input expressed in Volts.

%in
Relative input value. A value of 100% means that voltage
input has reached its high limit (in_max) whereas a value
of 0% means that it has reached its low limit (in_min).

DEVICE
Sensor device name.

With the TEMP keyword, statistics about devices temperature are
reported. The following values are displayed:

degC
Device temperature expressed in degrees Celsius.

%temp
Relative device temperature. A value of 100% means that
temperature has reached its high limit (temp_max).

DEVICE
Sensor device name.

With the USB keyword, the sar command takes a snapshot of all
the USB devices currently plugged into the system. At the end of
the report, sar will display a summary of all those USB devices.
The following values are displayed:

BUS
Root hub number of the USB device.

idvendor
Vendor ID number (assigned by USB organization).

idprod
Product ID number (assigned by Manufacturer).

maxpower
Maximum power consumption of the device (expressed in
mA).

manufact
Manufacturer name.

product
Product name.

The ALL keyword is equivalent to specifying all the keywords
above and therefore all the power management statistics are
reported.

-n { keyword [,…] | ALL }
Report network statistics.

Possible keywords are DEV, EDEV, NFS, NFSD, SOCK, IP, EIP, ICMP,
EICMP, TCP, ETCP, UDP, SOCK6, IP6, EIP6, ICMP6, EICMP6, UDP6 and
FC.

With the DEV keyword, statistics from the network devices are
reported. The following values are displayed:

IFACE
Name of the network interface for which statistics are
reported.

rxpck/s
Total number of packets received per second.

txpck/s
Total number of packets transmitted per second.

rxkB/s
Total number of kilobytes received per second.

txkB/s
Total number of kilobytes transmitted per second.

rxcmp/s
Number of compressed packets received per second (for
cslip etc.).

txcmp/s
Number of compressed packets transmitted per second.

rxmcst/s
Number of multicast packets received per second.

%ifutil
Utilization percentage of the network interface. For
half-duplex interfaces, utilization is calculated using
the sum of rxkB/s and txkB/s as a percentage of the
interface speed. For full-duplex, this is the greater of
rxkB/S or txkB/s.

With the EDEV keyword, statistics on failures (errors) from the
network devices are reported. The following values are dis‐
played:

IFACE
Name of the network interface for which statistics are
reported.

rxerr/s
Total number of bad packets received per second.

txerr/s
Total number of errors that happened per second while
transmitting packets.

coll/s
Number of collisions that happened per second while
transmitting packets.

rxdrop/s
Number of received packets dropped per second because of
a lack of space in linux buffers.

txdrop/s
Number of transmitted packets dropped per second because
of a lack of space in linux buffers.

txcarr/s
Number of carrier-errors that happened per second while
transmitting packets.

rxfram/s
Number of frame alignment errors that happened per second
on received packets.

rxfifo/s
Number of FIFO overrun errors that happened per second on
received packets.

txfifo/s
Number of FIFO overrun errors that happened per second on
transmitted packets.

With the NFS keyword, statistics about NFS client activity are
reported. The following values are displayed:

call/s
Number of RPC requests made per second.

retrans/s
Number of RPC requests per second, those which needed to
be retransmitted (for example because of a server time‐
out).

read/s
Number of ‘read’ RPC calls made per second.

write/s
Number of ‘write’ RPC calls made per second.

access/s
Number of ‘access’ RPC calls made per second.

getatt/s
Number of ‘getattr’ RPC calls made per second.

With the NFSD keyword, statistics about NFS server activity are
reported. The following values are displayed:

scall/s
Number of RPC requests received per second.

badcall/s
Number of bad RPC requests received per second, those
whose processing generated an error.

packet/s
Number of network packets received per second.

udp/s
Number of UDP packets received per second.

tcp/s
Number of TCP packets received per second.

hit/s
Number of reply cache hits per second.

miss/s
Number of reply cache misses per second.

sread/s
Number of ‘read’ RPC calls received per second.

swrite/s
Number of ‘write’ RPC calls received per second.

saccess/s
Number of ‘access’ RPC calls received per second.

sgetatt/s
Number of ‘getattr’ RPC calls received per second.

With the SOCK keyword, statistics on sockets in use are reported
(IPv4). The following values are displayed:

totsck
Total number of sockets used by the system.

tcpsck
Number of TCP sockets currently in use.

udpsck
Number of UDP sockets currently in use.

rawsck
Number of RAW sockets currently in use.

ip-frag
Number of IP fragments currently in queue.

tcp-tw
Number of TCP sockets in TIME_WAIT state.

With the IP keyword, statistics about IPv4 network traffic are
reported. Note that IPv4 statistics depend on sadc’s option “-S
SNMP” to be collected. The following values are displayed (for‐
mal SNMP names between square brackets):

irec/s
The total number of input datagrams received from inter‐
faces per second, including those received in error
[ipInReceives].

fwddgm/s
The number of input datagrams per second, for which this
entity was not their final IP destination, as a result of
which an attempt was made to find a route to forward them
to that final destination [ipForwDatagrams].

idel/s
The total number of input datagrams successfully deliv‐
ered per second to IP user-protocols (including ICMP)
[ipInDelivers].

orq/s
The total number of IP datagrams which local IP user-pro‐
tocols (including ICMP) supplied per second to IP in
requests for transmission [ipOutRequests]. Note that
this counter does not include any datagrams counted in
fwddgm/s.

asmrq/s
The number of IP fragments received per second which
needed to be reassembled at this entity [ipReasmReqds].

asmok/s
The number of IP datagrams successfully re-assembled per
second [ipReasmOKs].

fragok/s
The number of IP datagrams that have been successfully
fragmented at this entity per second [ipFragOKs].

fragcrt/s
The number of IP datagram fragments that have been gener‐
ated per second as a result of fragmentation at this
entity [ipFragCreates].

With the EIP keyword, statistics about IPv4 network errors are
reported. Note that IPv4 statistics depend on sadc’s option “-S
SNMP” to be collected. The following values are displayed (for‐
mal SNMP names between square brackets):

ihdrerr/s
The number of input datagrams discarded per second due to
errors in their IP headers, including bad checksums, ver‐
sion number mismatch, other format errors, time-to-live
exceeded, errors discovered in processing their IP
options, etc. [ipInHdrErrors]

iadrerr/s
The number of input datagrams discarded per second
because the IP address in their IP header’s destination
field was not a valid address to be received at this
entity. This count includes invalid addresses (e.g.,
0.0.0.0) and addresses of unsupported Classes (e.g.,
Class E). For entities which are not IP routers and
therefore do not forward datagrams, this counter includes
datagrams discarded because the destination address was
not a local address [ipInAddrErrors].

iukwnpr/s
The number of locally-addressed datagrams received suc‐
cessfully but discarded per second because of an unknown
or unsupported protocol [ipInUnknownProtos].

idisc/s
The number of input IP datagrams per second for which no
problems were encountered to prevent their continued pro‐
cessing, but which were discarded (e.g., for lack of buf‐
fer space) [ipInDiscards]. Note that this counter does
not include any datagrams discarded while awaiting
re-assembly.

odisc/s
The number of output IP datagrams per second for which no
problem was encountered to prevent their transmission to
their destination, but which were discarded (e.g., for
lack of buffer space) [ipOutDiscards]. Note that this
counter would include datagrams counted in fwddgm/s if
any such packets met this (discretionary) discard crite‐
rion.

onort/s
The number of IP datagrams discarded per second because
no route could be found to transmit them to their desti‐
nation [ipOutNoRoutes]. Note that this counter includes
any packets counted in fwddgm/s which meet this
‘no-route’ criterion. Note that this includes any data‐
grams which a host cannot route because all of its
default routers are down.

asmf/s
The number of failures detected per second by the IP
re-assembly algorithm (for whatever reason: timed out,
errors, etc) [ipReasmFails]. Note that this is not nec‐
essarily a count of discarded IP fragments since some
algorithms can lose track of the number of fragments by
combining them as they are received.

fragf/s
The number of IP datagrams that have been discarded per
second because they needed to be fragmented at this
entity but could not be, e.g., because their Don’t Frag‐
ment flag was set [ipFragFails].

With the ICMP keyword, statistics about ICMPv4 network traffic
are reported. Note that ICMPv4 statistics depend on sadc’s
option “-S SNMP” to be collected. The following values are dis‐
played (formal SNMP names between square brackets):

imsg/s
The total number of ICMP messages which the entity
received per second [icmpInMsgs]. Note that this counter
includes all those counted by ierr/s.

omsg/s
The total number of ICMP messages which this entity
attempted to send per second [icmpOutMsgs]. Note that
this counter includes all those counted by oerr/s.

iech/s
The number of ICMP Echo (request) messages received per
second [icmpInEchos].

iechr/s
The number of ICMP Echo Reply messages received per sec‐
ond [icmpInEchoReps].

oech/s
The number of ICMP Echo (request) messages sent per sec‐
ond [icmpOutEchos].

oechr/s
The number of ICMP Echo Reply messages sent per second
[icmpOutEchoReps].

itm/s
The number of ICMP Timestamp (request) messages received
per second [icmpInTimestamps].

itmr/s
The number of ICMP Timestamp Reply messages received per
second [icmpInTimestampReps].

otm/s
The number of ICMP Timestamp (request) messages sent per
second [icmpOutTimestamps].

otmr/s
The number of ICMP Timestamp Reply messages sent per sec‐
ond [icmpOutTimestampReps].

iadrmk/s
The number of ICMP Address Mask Request messages received
per second [icmpInAddrMasks].

iadrmkr/s
The number of ICMP Address Mask Reply messages received
per second [icmpInAddrMaskReps].

oadrmk/s
The number of ICMP Address Mask Request messages sent per
second [icmpOutAddrMasks].

oadrmkr/s
The number of ICMP Address Mask Reply messages sent per
second [icmpOutAddrMaskReps].

With the EICMP keyword, statistics about ICMPv4 error messages
are reported. Note that ICMPv4 statistics depend on sadc’s
option “-S SNMP” to be collected. The following values are dis‐
played (formal SNMP names between square brackets):

ierr/s
The number of ICMP messages per second which the entity
received but determined as having ICMP-specific errors
(bad ICMP checksums, bad length, etc.) [icmpInErrors].

oerr/s
The number of ICMP messages per second which this entity
did not send due to problems discovered within ICMP such
as a lack of buffers [icmpOutErrors].

idstunr/s
The number of ICMP Destination Unreachable messages
received per second [icmpInDestUnreachs].

odstunr/s
The number of ICMP Destination Unreachable messages sent
per second [icmpOutDestUnreachs].

itmex/s
The number of ICMP Time Exceeded messages received per
second [icmpInTimeExcds].

otmex/s
The number of ICMP Time Exceeded messages sent per second
[icmpOutTimeExcds].

iparmpb/s
The number of ICMP Parameter Problem messages received
per second [icmpInParmProbs].

oparmpb/s
The number of ICMP Parameter Problem messages sent per
second [icmpOutParmProbs].

isrcq/s
The number of ICMP Source Quench messages received per
second [icmpInSrcQuenchs].

osrcq/s
The number of ICMP Source Quench messages sent per second
[icmpOutSrcQuenchs].

iredir/s
The number of ICMP Redirect messages received per second
[icmpInRedirects].

oredir/s
The number of ICMP Redirect messages sent per second
[icmpOutRedirects].

With the TCP keyword, statistics about TCPv4 network traffic are
reported. Note that TCPv4 statistics depend on sadc’s option
“-S SNMP” to be collected. The following values are displayed
(formal SNMP names between square brackets):

active/s
The number of times TCP connections have made a direct
transition to the SYN-SENT state from the CLOSED state
per second [tcpActiveOpens].

passive/s
The number of times TCP connections have made a direct
transition to the SYN-RCVD state from the LISTEN state
per second [tcpPassiveOpens].

iseg/s
The total number of segments received per second, includ‐
ing those received in error [tcpInSegs]. This count
includes segments received on currently established con‐
nections.

oseg/s
The total number of segments sent per second, including
those on current connections but excluding those contain‐
ing only retransmitted octets [tcpOutSegs].

With the ETCP keyword, statistics about TCPv4 network errors are
reported. Note that TCPv4 statistics depend on sadc’s option
“-S SNMP” to be collected. The following values are displayed
(formal SNMP names between square brackets):

atmptf/s
The number of times per second TCP connections have made
a direct transition to the CLOSED state from either the
SYN-SENT state or the SYN-RCVD state, plus the number of
times per second TCP connections have made a direct tran‐
sition to the LISTEN state from the SYN-RCVD state
[tcpAttemptFails].

estres/s
The number of times per second TCP connections have made
a direct transition to the CLOSED state from either the
ESTABLISHED state or the CLOSE-WAIT state [tcpEstabRe‐
sets].

retrans/s
The total number of segments retransmitted per second –
that is, the number of TCP segments transmitted contain‐
ing one or more previously transmitted octets [tcpRe‐
transSegs].

isegerr/s
The total number of segments received in error (e.g., bad
TCP checksums) per second [tcpInErrs].

orsts/s
The number of TCP segments sent per second containing the
RST flag [tcpOutRsts].

With the UDP keyword, statistics about UDPv4 network traffic are
reported. Note that UDPv4 statistics depend on sadc’s option
“-S SNMP” to be collected. The following values are displayed
(formal SNMP names between square brackets):

idgm/s
The total number of UDP datagrams delivered per second to
UDP users [udpInDatagrams].

odgm/s
The total number of UDP datagrams sent per second from
this entity [udpOutDatagrams].

noport/s
The total number of received UDP datagrams per second for
which there was no application at the destination port
[udpNoPorts].

idgmerr/s
The number of received UDP datagrams per second that
could not be delivered for reasons other than the lack of
an application at the destination port [udpInErrors].

With the SOCK6 keyword, statistics on sockets in use are
reported (IPv6). Note that IPv6 statistics depend on sadc’s
option “-S IPV6” to be collected. The following values are dis‐
played:

tcp6sck
Number of TCPv6 sockets currently in use.

udp6sck
Number of UDPv6 sockets currently in use.

raw6sck
Number of RAWv6 sockets currently in use.

ip6-frag
Number of IPv6 fragments currently in use.

With the IP6 keyword, statistics about IPv6 network traffic are
reported. Note that IPv6 statistics depend on sadc’s option “-S
IPV6” to be collected. The following values are displayed (for‐
mal SNMP names between square brackets):

irec6/s
The total number of input datagrams received from inter‐
faces per second, including those received in error
[ipv6IfStatsInReceives].

fwddgm6/s
The number of output datagrams per second which this
entity received and forwarded to their final destinations
[ipv6IfStatsOutForwDatagrams].

idel6/s
The total number of datagrams successfully delivered per
second to IPv6 user-protocols (including ICMP) [ipv6IfS‐
tatsInDelivers].

orq6/s
The total number of IPv6 datagrams which local IPv6
user-protocols (including ICMP) supplied per second to
IPv6 in requests for transmission [ipv6IfStatsOutRe‐
quests]. Note that this counter does not include any
datagrams counted in fwddgm6/s.

asmrq6/s
The number of IPv6 fragments received per second which
needed to be reassembled at this interface [ipv6IfStat‐
sReasmReqds].

asmok6/s
The number of IPv6 datagrams successfully reassembled per
second [ipv6IfStatsReasmOKs].

imcpck6/s
The number of multicast packets received per second by
the interface [ipv6IfStatsInMcastPkts].

omcpck6/s
The number of multicast packets transmitted per second by
the interface [ipv6IfStatsOutMcastPkts].

fragok6/s
The number of IPv6 datagrams that have been successfully
fragmented at this output interface per second [ipv6IfS‐
tatsOutFragOKs].

fragcr6/s
The number of output datagram fragments that have been
generated per second as a result of fragmentation at this
output interface [ipv6IfStatsOutFragCreates].

With the EIP6 keyword, statistics about IPv6 network errors are
reported. Note that IPv6 statistics depend on sadc’s option “-S
IPV6” to be collected. The following values are displayed (for‐
mal SNMP names between square brackets):

ihdrer6/s
The number of input datagrams discarded per second due to
errors in their IPv6 headers, including version number
mismatch, other format errors, hop count exceeded, errors
discovered in processing their IPv6 options, etc.
[ipv6IfStatsInHdrErrors]

iadrer6/s
The number of input datagrams discarded per second
because the IPv6 address in their IPv6 header’s destina‐
tion field was not a valid address to be received at this
entity. This count includes invalid addresses (e.g., ::0)
and unsupported addresses (e.g., addresses with unallo‐
cated prefixes). For entities which are not IPv6 routers
and therefore do not forward datagrams, this counter
includes datagrams discarded because the destination
address was not a local address [ipv6IfStatsInAddr‐
Errors].

iukwnp6/s
The number of locally-addressed datagrams received suc‐
cessfully but discarded per second because of an unknown
or unsupported protocol [ipv6IfStatsInUnknownProtos].

i2big6/s
The number of input datagrams that could not be forwarded
per second because their size exceeded the link MTU of
outgoing interface [ipv6IfStatsInTooBigErrors].

idisc6/s
The number of input IPv6 datagrams per second for which
no problems were encountered to prevent their continued
processing, but which were discarded (e.g., for lack of
buffer space) [ipv6IfStatsInDiscards]. Note that this
counter does not include any datagrams discarded while
awaiting re-assembly.

odisc6/s
The number of output IPv6 datagrams per second for which
no problem was encountered to prevent their transmission
to their destination, but which were discarded (e.g., for
lack of buffer space) [ipv6IfStatsOutDiscards]. Note that
this counter would include datagrams counted in fwddgm6/s
if any such packets met this (discretionary) discard cri‐
terion.

inort6/s
The number of input datagrams discarded per second
because no route could be found to transmit them to their
destination [ipv6IfStatsInNoRoutes].

onort6/s
The number of locally generated IP datagrams discarded
per second because no route could be found to transmit
them to their destination [unknown formal SNMP name].

asmf6/s
The number of failures detected per second by the IPv6
re-assembly algorithm (for whatever reason: timed out,
errors, etc.) [ipv6IfStatsReasmFails]. Note that this is
not necessarily a count of discarded IPv6 fragments since
some algorithms can lose track of the number of fragments
by combining them as they are received.

fragf6/s
The number of IPv6 datagrams that have been discarded per
second because they needed to be fragmented at this out‐
put interface but could not be [ipv6IfStatsOutFragFails].

itrpck6/s
The number of input datagrams discarded per second
because datagram frame didn’t carry enough data [ipv6IfS‐
tatsInTruncatedPkts].

With the ICMP6 keyword, statistics about ICMPv6 network traffic
are reported. Note that ICMPv6 statistics depend on sadc’s
option “-S IPV6” to be collected. The following values are dis‐
played (formal SNMP names between square brackets):

imsg6/s
The total number of ICMP messages received by the inter‐
face per second which includes all those counted by
ierr6/s [ipv6IfIcmpInMsgs].

omsg6/s
The total number of ICMP messages which this interface
attempted to send per second [ipv6IfIcmpOutMsgs].

iech6/s
The number of ICMP Echo (request) messages received by
the interface per second [ipv6IfIcmpInEchos].

iechr6/s
The number of ICMP Echo Reply messages received by the
interface per second [ipv6IfIcmpInEchoReplies].

oechr6/s
The number of ICMP Echo Reply messages sent by the inter‐
face per second [ipv6IfIcmpOutEchoReplies].

igmbq6/s
The number of ICMPv6 Group Membership Query messages
received by the interface per second [ipv6IfIcmpInGroup‐
MembQueries].

igmbr6/s
The number of ICMPv6 Group Membership Response messages
received by the interface per second [ipv6IfIcmpInGroup‐
MembResponses].

ogmbr6/s
The number of ICMPv6 Group Membership Response messages
sent per second [ipv6IfIcmpOutGroupMembResponses].

igmbrd6/s
The number of ICMPv6 Group Membership Reduction messages
received by the interface per second [ipv6IfIcmpInGroup‐
MembReductions].

ogmbrd6/s
The number of ICMPv6 Group Membership Reduction messages
sent per second [ipv6IfIcmpOutGroupMembReductions].

irtsol6/s
The number of ICMP Router Solicit messages received by
the interface per second [ipv6IfIcmpInRouterSolicits].

ortsol6/s
The number of ICMP Router Solicitation messages sent by
the interface per second [ipv6IfIcmpOutRouterSolicits].

irtad6/s
The number of ICMP Router Advertisement messages received
by the interface per second [ipv6IfIcmpInRouterAdvertise‐
ments].

inbsol6/s
The number of ICMP Neighbor Solicit messages received by
the interface per second [ipv6IfIcmpInNeighborSolicits].

onbsol6/s
The number of ICMP Neighbor Solicitation messages sent by
the interface per second [ipv6IfIcmpOutNeighborSolicits].

inbad6/s
The number of ICMP Neighbor Advertisement messages
received by the interface per second [ipv6IfIcmpInNeighb‐
orAdvertisements].

onbad6/s
The number of ICMP Neighbor Advertisement messages sent
by the interface per second [ipv6IfIcmpOutNeighborAdver‐
tisements].

With the EICMP6 keyword, statistics about ICMPv6 error messages
are reported. Note that ICMPv6 statistics depend on sadc’s
option “-S IPV6” to be collected. The following values are dis‐
played (formal SNMP names between square brackets):

ierr6/s
The number of ICMP messages per second which the inter‐
face received but determined as having ICMP-specific
errors (bad ICMP checksums, bad length, etc.)
[ipv6IfIcmpInErrors]

idtunr6/s
The number of ICMP Destination Unreachable messages
received by the interface per second [ipv6IfIcmpInDestUn‐
reachs].

odtunr6/s
The number of ICMP Destination Unreachable messages sent
by the interface per second [ipv6IfIcmpOutDestUnreachs].

itmex6/s
The number of ICMP Time Exceeded messages received by the
interface per second [ipv6IfIcmpInTimeExcds].

otmex6/s
The number of ICMP Time Exceeded messages sent by the
interface per second [ipv6IfIcmpOutTimeExcds].

iprmpb6/s
The number of ICMP Parameter Problem messages received by
the interface per second [ipv6IfIcmpInParmProblems].

oprmpb6/s
The number of ICMP Parameter Problem messages sent by the
interface per second [ipv6IfIcmpOutParmProblems].

iredir6/s
The number of Redirect messages received by the interface
per second [ipv6IfIcmpInRedirects].

oredir6/s
The number of Redirect messages sent by the interface by
second [ipv6IfIcmpOutRedirects].

ipck2b6/s
The number of ICMP Packet Too Big messages received by
the interface per second [ipv6IfIcmpInPktTooBigs].

opck2b6/s
The number of ICMP Packet Too Big messages sent by the
interface per second [ipv6IfIcmpOutPktTooBigs].

With the UDP6 keyword, statistics about UDPv6 network traffic
are reported. Note that UDPv6 statistics depend on sadc’s
option “-S IPV6” to be collected. The following values are dis‐
played (formal SNMP names between square brackets):

idgm6/s
The total number of UDP datagrams delivered per second to
UDP users [udpInDatagrams].

odgm6/s
The total number of UDP datagrams sent per second from
this entity [udpOutDatagrams].

noport6/s
The total number of received UDP datagrams per second for
which there was no application at the destination port
[udpNoPorts].

idgmer6/s
The number of received UDP datagrams per second that
could not be delivered for reasons other than the lack of
an application at the destination port [udpInErrors].

With the FC keyword, statistics about fibre channel traffic are
reported. Note that fibre channel statistics depend on sadc’s
option “-S DISK” to be collected. The following values are dis‐
played:

FCHOST
Name of the fibre channel host bus adapter (HBA) inter‐
face for which statistics are reported.

fch_rxf/s
The total number of frames received per second.

fch_txf/s
The total number of frames transmitted per second.

fch_rxw/s
The total number of transmission words received per sec‐
ond.

fch_txw/s
The total number of transmission words transmitted per
second.

The ALL keyword is equivalent to specifying all the keywords
above and therefore all the network activities are reported.

-o [ filename ] Save the readings in the file in binary form. Each reading is in
a separate record. The default value of the filename parameter
is the current standard system activity daily data file. If
filename is a directory instead of a plain file then it is con‐
sidered as the directory where the standard system activity
daily data files are located. The -o option is exclusive of the
-f option. All the data available from the kernel are saved in
the file (in fact, sar calls its data collector sadc with the
option “-S ALL”. See sadc(8) manual page).

-P { cpu [,…] | ALL }
Report per-processor statistics for the specified processor or
processors. Specifying the ALL keyword reports statistics for
each individual processor, and globally for all processors.
Note that processor 0 is the first processor.

-p Pretty-print device names. Use this option in conjunction with
option -d. By default names are printed as devM-n where M and n
are the major and minor numbers for the device. Use of this
option displays the names of the devices as they (should) appear
in /dev. Name mappings are controlled by /etc/sysstat/sys‐
stat.ioconf.

-q Report queue length and load averages. The following values are
displayed:

runq-sz
Run queue length (number of tasks waiting for run time).

plist-sz
Number of tasks in the task list.

ldavg-1
System load average for the last minute. The load aver‐
age is calculated as the average number of runnable or
running tasks (R state), and the number of tasks in unin‐
terruptible sleep (D state) over the specified interval.

ldavg-5
System load average for the past 5 minutes.

ldavg-15
System load average for the past 15 minutes.

blocked
Number of tasks currently blocked, waiting for I/O to
complete.

-R Report memory statistics. The following values are displayed:

frmpg/s
Number of memory pages freed by the system per second. A
negative value represents a number of pages allocated by
the system. Note that a page has a size of 4 kiB or 8
kiB according to the machine architecture.

bufpg/s
Number of additional memory pages used as buffers by the
system per second. A negative value means fewer pages
used as buffers by the system.

campg/s
Number of additional memory pages cached by the system
per second. A negative value means fewer pages in the
cache.

-r [ ALL ] Report memory utilization statistics. The ALL keyword indicates
that all the memory fields should be displayed. The following
values may be displayed:

kbmemfree
Amount of free memory available in kilobytes.

kbmemused
Amount of used memory in kilobytes. This does not take
into account memory used by the kernel itself.

%memused
Percentage of used memory.

kbbuffers
Amount of memory used as buffers by the kernel in kilo‐
bytes.

kbcached
Amount of memory used to cache data by the kernel in
kilobytes.

kbcommit
Amount of memory in kilobytes needed for current work‐
load. This is an estimate of how much RAM/swap is needed
to guarantee that there never is out of memory.

%commit
Percentage of memory needed for current workload in rela‐
tion to the total amount of memory (RAM+swap). This num‐
ber may be greater than 100% because the kernel usually
overcommits memory.

kbactive
Amount of active memory in kilobytes (memory that has
been used more recently and usually not reclaimed unless
absolutely necessary).

kbinact
Amount of inactive memory in kilobytes (memory which has
been less recently used. It is more eligible to be
reclaimed for other purposes).

kbdirty
Amount of memory in kilobytes waiting to get written back
to the disk.

kbanonpg
Amount of non-file backed pages in kilobytes mapped into
userspace page tables.

kbslab
Amount of memory in kilobytes used by the kernel to cache
data structures for its own use.

kbkstack
Amount of memory in kilobytes used for kernel stack
space.

kbpgtbl
Amount of memory in kilobytes dedicated to the lowest
level of page tables.

kbvmused
Amount of memory in kilobytes of used virtual address
space.

-S Report swap space utilization statistics. The following values
are displayed:

kbswpfree
Amount of free swap space in kilobytes.

kbswpused
Amount of used swap space in kilobytes.

%swpused
Percentage of used swap space.

kbswpcad
Amount of cached swap memory in kilobytes. This is mem‐
ory that once was swapped out, is swapped back in but
still also is in the swap area (if memory is needed it
doesn’t need to be swapped out again because it is
already in the swap area. This saves I/O).

%swpcad
Percentage of cached swap memory in relation to the
amount of used swap space.

-s [ hh:mm[:ss] ] Set the starting time of the data, causing the sar command to
extract records time-tagged at, or following, the time speci‐
fied. The default starting time is 08:00:00. Hours must be
given in 24-hour format. This option can be used only when data
are read from a file (option -f).

–sadc Indicate which data collector is called by sar. If the data
collector is sought in PATH then enter “which sadc” to know
where it is located.

-t When reading data from a daily data file, indicate that sar
should display the timestamps in the original local time of the
data file creator. Without this option, the sar command displays
the timestamps in the user’s locale time.

-u [ ALL ] Report CPU utilization. The ALL keyword indicates that all the
CPU fields should be displayed. The report may show the follow‐
ing fields:

%user
Percentage of CPU utilization that occurred while execut‐
ing at the user level (application). Note that this field
includes time spent running virtual processors.

%usr
Percentage of CPU utilization that occurred while execut‐
ing at the user level (application). Note that this field
does NOT include time spent running virtual processors.

%nice
Percentage of CPU utilization that occurred while execut‐
ing at the user level with nice priority.

%system
Percentage of CPU utilization that occurred while execut‐
ing at the system level (kernel). Note that this field
includes time spent servicing hardware and software
interrupts.

%sys
Percentage of CPU utilization that occurred while execut‐
ing at the system level (kernel). Note that this field
does NOT include time spent servicing hardware or soft‐
ware interrupts.

%iowait
Percentage of time that the CPU or CPUs were idle during
which the system had an outstanding disk I/O request.

%steal
Percentage of time spent in involuntary wait by the vir‐
tual CPU or CPUs while the hypervisor was servicing
another virtual processor.

%irq
Percentage of time spent by the CPU or CPUs to service
hardware interrupts.

%soft
Percentage of time spent by the CPU or CPUs to service
software interrupts.

%guest
Percentage of time spent by the CPU or CPUs to run a vir‐
tual processor.

%gnice
Percentage of time spent by the CPU or CPUs to run a
niced guest.

%idle
Percentage of time that the CPU or CPUs were idle and the
system did not have an outstanding disk I/O request.

Note: On SMP machines a processor that does not have any activ‐
ity at all (0.00 for every field) is a disabled (offline) pro‐
cessor.

-V Print version number then exit.

-v Report status of inode, file and other kernel tables. The fol‐
lowing values are displayed:

dentunusd
Number of unused cache entries in the directory cache.

file-nr
Number of file handles used by the system.

inode-nr
Number of inode handlers used by the system.

pty-nr
Number of pseudo-terminals used by the system.

-W Report swapping statistics. The following values are displayed:

pswpin/s
Total number of swap pages the system brought in per sec‐
ond.

pswpout/s
Total number of swap pages the system brought out per
second.

-w Report task creation and system switching activity.

proc/s
Total number of tasks created per second.

cswch/s
Total number of context switches per second.

-y Report TTY devices activity. The following values are displayed:

rcvin/s
Number of receive interrupts per second for current
serial line. Serial line number is given in the TTY col‐
umn.

xmtin/s
Number of transmit interrupts per second for current
serial line.

framerr/s
Number of frame errors per second for current serial
line.

prtyerr/s
Number of parity errors per second for current serial
line.

brk/s
Number of breaks per second for current serial line.

ovrun/s
Number of overrun errors per second for current serial
line.

ENVIRONMENT
The sar command takes into account the following environment variables:

S_COLORS
When this variable is set, display statistics in color on the
terminal. Possible values for this variable are never, always
or auto (the latter is the default).

Please note that the color (being red, yellow, or some other
color) used to display a value is not indicative of any kind of
issue simply because of the color. It only indicates different
ranges of values.

S_COLORS_SGR
Specify the colors and other attributes used to display statis‐
tics on the terminal. Its value is a colon-separated list of
capabilities that defaults to
C=36;22:H=31;1:I=32;22:M=34;1:N=33;1:R=31;22:Z=33;22. Supported
capabilities are:

C= SGR (Select Graphic Rendition) substring for comments
inserted in the binary daily data files.

H= SGR substring for percentage values greater than or equal
to 75%.

I= SGR substring for item names or values (eg. network
interfaces, CPU number…)

M= SGR substring for percentage values in the range from 50%
to 75%.

N= SGR substring for non-zero statistics values.

R= SGR substring for restart messages.

Z= SGR substring for zero values.

S_TIME_DEF_TIME
If this variable exists and its value is UTC then sar will save
its data in UTC time (data will still be displayed in local
time). sar will also use UTC time instead of local time to
determine the current daily data file located in the
/var/log/sysstat directory. This variable may be useful for
servers with users located across several timezones.

S_TIME_FORMAT
If this variable exists and its value is ISO then the current
locale will be ignored when printing the date in the report
header. The sar command will use the ISO 8601 format
(YYYY-MM-DD) instead.

EXAMPLES
sar -u 2 5
Report CPU utilization for each 2 seconds. 5 lines are dis‐
played.

sar -I 14 -o int14.file 2 10
Report statistics on IRQ 14 for each 2 seconds. 10 lines are
displayed. Data are stored in a file called int14.file.

sar -r -n DEV -f /var/log/sysstat/sa16
Display memory and network statistics saved in daily data file
‘sa16’.

sar -A
Display all the statistics saved in current daily data file.

BUGS

/proc filesystem must be mounted for the sar command to work.

All the statistics are not necessarily available, depending on the ker‐
nel version used. sar assumes that you are using at least a 2.6 ker‐
nel.

FILES
/var/log/sysstat/saDD
/var/log/sysstat/saYYYYMMDD
The standard system activity daily data files and their default
location. YYYY stands for the current year, MM for the current
month and DD for the current day.

/proc and /sys contain various files with system statistics.

AUTHOR

Sebastien Godard (sysstat orange.fr)

SEE ALSO

sadc(8), sa1(8), sa2(8), sadf, pidstat, mpstat, iostat,
vmstat(8)

http://pagesperso-orange.fr/sebastien.godard/

Linux OCTOBER 2015 SAR(1)