Most of the files at the top-level of the /proc
directory hold key pieces of information about the state of the Linux
kernel and your system in general.
It is important to remember that the content of the files in the
/proc directory and its various sub-directories is
entirely dependent on information concerning your system. In other
words, do not expect to see the exact same information in the same
/proc file on two different machines. In addition,
depending on the version of the Linux kernel and the devices connected
to your system, some of the files described here may not be found in
your /proc directory. Likewise, additional files or
directories may be on your system but are not described here.
Rather than attempting to be a comprehensive collection of these files
and the information they contain, the following list is designed to
showcase some of the more common and useful ones. The objective is to
provide system administrators with a place to find current data on their
systems when other tools will not do the job.
This file provides information about the Advanced Power
Management (APM) state and options on the system. This
information is used by the kernel to provide information for the
apm command.
The output of this file on a system without a battery and constantly
connected to an AC power source looks similar to this:
1.14 1.2 0x03 0x01 0xff 0x80 -1% -1 ? |
Executing an apm command on these systems results
in something similar to this:
[root@bleach /proc]# apm -v
APM BIOS 1.2 (kernel driver 1.14)
AC on-line, no system battery
[root@bleach /proc]# |
For these systems, apm may be able to do little
more than put the machine in a standby
mode, commonly known as "putting the system to sleep." Note that
this state is only possible if your system BIOS supports it. Trying
to put a system in standby mode that is not designed for it can make
the system unstable.
The apm command is much more useful on laptops
and other portable Linux systems. This is also reflected in their
/proc/apm files. This is the output from a
sample file on a laptop running Linux while plugged into a power
outlet:
1.14 1.2 0x03 0x01 0x03 0x09 100% -1 ? |
When the same machine is unplugged from its power source and running
on its own batteries for a few minutes, you will see the contents of
the apm file change:
1.14 1.2 0x03 0x00 0x00 0x01 99% 1792 min |
In this state, the apm command yields readable
information from this data:
[ed@blink /]$ apm -v
APM BIOS 1.2 (kernel driver 1.14)
AC off-line, battery status high: 99% (1 day, 5:52)
[ed@blink /]$ |
This demonstrates the connection between data located in raw
/proc files and the utilities designed to use
that information for specific purposes.
This file essentially shows the parameters passed to the Linux
kernel at the time it is started. A sample
/proc/cmdline file looks similar to this:
auto BOOT_IMAGE=linux ro root=305 BOOT_FILE=/boot/vmlinuz-2.4.2-2 |
The important data contained in the file breaks down in the
following way:
BOOT_IMAGE=linux, which tells
you the name of the image used to boot the machine.
ro, which signifies that the
kernel is loaded read-only.
BOOT_FILE=/boot/vmlinuz-2.4.2-2
notes the actual Linux kernel file used to boot the
system.
This file changes based on the type of processor in your
system. The output is fairly easy to understand. A sample file looks
like this:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 6
model name : Celeron (Mendocino)
stepping : 0
cpu MHz : 334.099
cache size : 128 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov
bogomips : 666.82 |
Quite a bit of information is available here. Among the highlights:
processor — Provides each
processor with an identifying number. If you only have one
processor, you will only see a
0. However, if you are using
a machine with multiple processors, each of the processors
will have it own number, increasing by one as you go down the
list, and its own collection of information.
cpu family —
Authoritatively tells you the type of processor you have in
the system. Simply place the number in front of "86" to
calculate the value. This is particularly helpful if you are
wondering about the architecture of an older system (686, 586,
486, or 386). As RPM packages are occasionally compiled for
particular architectures, this value tells you which package
to install on the system.
model name — Gives you
the popular name of the processor, including its project name.
cpu MHz — Shows the
precise speed in megahertz of that particular processor (in thousandths).
cache size — Tells you
the amount of level 2 memory cache available to the processor.
flags — Defines a number
of different qualities about the processor, such as the
presence of a floating point unit (FPU) and the ability to
process MMX instructions.
This file displays the various character and block devices currently
configured for use with the kernel. It does not include modules that
are available but not loaded into the kernel. Sample output from
this file looks similar to this:
Character devices:
1 mem
2 pty
3 ttyp
4 ttyS
5 cua
7 vcs
10 misc
29 fb
36 netlink
128 ptm
136 pts
162 raw
180 usb
Block devices:
1 ramdisk
2 fd
3 ide0
9 md
22 ide1 |
The output from /proc/devices includes the
major number and name of the device.
Character devices are similar to
block devices, except for two basic
differences.
First, block devices have a buffer available for requests sent to
them, allowing them to order the requests before dealing with
them. This comes in very handy with devices designed to store
information, such as hard drives, because the ability to order the
information before writing it to the device allows it to be placed
in more efficient order. Character devices do not require this kind
of buffering.
Second, block devices can send and receive information in blocks of
a particular size, which can be configured to meet the requirements
of the particular device. Character devices send data in as many or
few bytes as they see fit, with no preconfigured size.
To discover if a particular device is a block or character device,
type the ls -l
<device-name> command. If
the first character in the response is a
b, then it is a block device; if it
is a c, then it is character
device. For example, note the output from a look at some common
devices (hda is the first IDE hard drive and
tty0 is the first terminal port) from the
/dev directory:
[root@bleach /]# ls -l /dev/hda /dev/tty0
brw-rw---- 1 root disk 3, 0 Mar 23 23:37 /dev/hda
crw--w---- 1 truk truk 4, 0 May 3 16:28 /dev/tty0
[root@bleach /]# |
More information about devices can be found in
/usr/src/linux-2.4/Documentation/devices.txt.
This file contains a list of the registered ISA direct memory access
(DMA) channels in use. A sample /proc/dma files
looks like this:
This file lists the execution domains currently supported by the
Linux kernel, along with the range of personalities they support.
Think of execution domains as a kind of
"personality" of a particular operating system. Other binary
formats, such as Solaris, UnixWare, and FreeBSD, can be used with
Linux. By changing the personality of a task running in Linux, a
programmer can change the way the operating system treats particular
system calls from a certain binary. Except for the
PER_LINUX execution domain, they
can be implemented as dynamically loadable modules.
This file contains a list of frame buffer devices, with the frame
buffer device number and the driver that controls it. Typical output
of /proc/fb for systems that contain frame buffer
devices looks similar to this:
This file displays a list of the filesystem types currently
supported by the kernel. Sample output from a generic kernel's
/proc/filesystems file looks similar to this:
nodev sockfs
nodev tmpfs
nodev shm
nodev pipefs
nodev proc
ext2
iso9660
nodev devpts
nodev usbdevfs
nodev autofs |
The first column signifies whether the filesystem is mounted on a
block device, with those containing
nodev in this column signifying that they
are not mounted on a block device. The second column lists the name
of the filesystems supported.
This information is used by the mount command to
cycle through the possible filesystems when one is not specified as
an argument.
This file records the number of interrupts per IRQ on the x86
architecture. A standard /proc/interrupts looks
similar to this:
CPU0
0: 8399367 XT-PIC timer
1: 339 XT-PIC keyboard
2: 0 XT-PIC cascade
5: 80111 XT-PIC usb-uhci, eth0
8: 1 XT-PIC rtc
12: 6107 XT-PIC PS/2 Mouse
14: 60324 XT-PIC ide0
15: 541741 XT-PIC ide1
NMI: 0
ERR: 0 |
For a multi-processor machine, this file may look slightly
different:
CPU0 CPU1
0: 1366814704 0 XT-PIC timer
1: 128 340 IO-APIC-edge keyboard
2: 0 0 XT-PIC cascade
8: 0 1 IO-APIC-edge rtc
12: 5323 5793 IO-APIC-edge PS/2 Mouse
13: 1 0 XT-PIC fpu
16: 11184294 15940594 IO-APIC-level Intel EtherExpress Pro 10/100 Ethernet
20: 8450043 11120093 IO-APIC-level megaraid
30: 10432 10722 IO-APIC-level aic7xxx
31: 23 22 IO-APIC-level aic7xxx
NMI: 0
ERR: 0 |
The first column refers to the IRQ number. Each CPU in the system has
its own column and its own number of interrupts per IRQ. The next
column tells you the type of interrupt, and the last column contains
the name of the device that is located at that IRQ.
Each of the types of interrupts seen in this file, which are
architecture-specific, mean something a little different. For x86
machines, the following values are common:
XT-PIC — The old AT
computer interrupts that have been around for a long time.
IO-APIC-edge — The voltage signal
on this interrupt transitions from low to high, creating an
edge, where the interrupt occurs and is
only signaled once. This kind of interrupt, as well as the
IO-APIC-level interrupt, are only
seen on systems with processors from the 586 family and higher.
IO-APIC-level — Generates
interrupts when its voltage signal goes high until the signal goes
low again.
This file shows you the current map of the system's memory for its
various devices:
00000000-0009fbff : System RAM
0009fc00-0009ffff : reserved
000a0000-000bffff : Video RAM area
000c0000-000c7fff : Video ROM
000f0000-000fffff : System ROM
00100000-03ffcfff : System RAM
00100000-002557df : Kernel code
002557e0-0026c80b : Kernel data
03ffd000-03ffefff : ACPI Tables
03fff000-03ffffff : ACPI Non-volatile Storage
dc000000-dfffffff : S3 Inc. ViRGE/DX or /GX
e3000000-e30000ff : Lite-On Communications Inc LNE100TX
e3000000-e30000ff : eth0
e4000000-e7ffffff : Intel Corporation 440BX/ZX - 82443BX/ZX Host bridge
ffff0000-ffffffff : reserved |
The first column displays the memory registers used by each of the
different types of memory. The second column tells the kind of
memory located within those registers. In particular, this column
will even tell you which memory registers are used by the kernel
within the system RAM or, if you have multiple Ethernet ports on
your NIC, the memory registers assigned for each port.
In a way similar to /proc/iomem,
/proc/ioports provides a list of currently
registered port regions used for input or output communication with
a device. This file can be quite long, with a beginning similar to
this:
0000-001f : dma1
0020-003f : pic1
0040-005f : timer
0060-006f : keyboard
0070-007f : rtc
0080-008f : dma page reg
00a0-00bf : pic2
00c0-00df : dma2
00f0-00ff : fpu
0170-0177 : ide1
01f0-01f7 : ide0 |
The first column gives the actual IO port address range reserved for
the device listed in the second column.
This file lists Plug and Play (PnP) cards in
ISA slots on the system. This is most often seen with sound cards but
may include any number of devices. A /proc/isapnp
file with Soundblaster entry in it looks similar to this:
Card 1 'CTL0070:Creative ViBRA16C PnP' PnP version 1.0 Product version 1.0
Logical device 0 'CTL0001:Audio'
Device is not active
Active port 0x220,0x330,0x388
Active IRQ 5 [0x2]
Active DMA 1,5
Resources 0
Priority preferred
Port 0x220-0x220, align 0x0, size 0x10, 16-bit address decoding
Port 0x330-0x330, align 0x0, size 0x2, 16-bit address decoding
Port 0x388-0x3f8, align 0x0, size 0x4, 16-bit address decoding
IRQ 5 High-Edge
DMA 1 8-bit byte-count compatible
DMA 5 16-bit word-count compatible
Alternate resources 0:1
Priority acceptable
Port 0x220-0x280, align 0x1f, size 0x10, 16-bit address decoding
Port 0x300-0x330, align 0x2f, size 0x2, 16-bit address decoding
Port 0x388-0x3f8, align 0x0, size 0x4, 16-bit address decoding
IRQ 5,7,2/9,10 High-Edge
DMA 1,3 8-bit byte-count compatible
DMA 5,7 16-bit word-count compatible |
This file can be quite long, depending on the number of devices
displayed here and their requirements or requests for resources.
Each card lists its name, PnP version number, and product version
number. If the device is active and configured, this file will also
reveal the port and IRQ numbers for the device. In addition, to
ensure better compatibility, the card will specify
preferred and
acceptable values for a number of
different parameters. The goal here is to allow the PnP cards to
work around one another and avoid IRQ and port conflicts.
This file represents the physical memory of the system and is stored
in the core file format. Unlike most /proc
files, kcore does display a size. This value is
given in bytes and is equal to the size of physical memory (RAM)
used plus 4KB.
Do not try to cat or otherwise attempt to view
this file. Its contents are designed to be examined by a debugger,
such as gdb, the GNU Debugger.
Only the root user has the rights to view this file.
This file is used to hold messages generated by the kernel. These
messages are then picked up by other programs, such as
klogd.
This file holds the kernel exported symbol definitions used by the
modules tools to dynamically link and bind loadable modules.
e003def4 speedo_debug [eepro100]
e003b04c eepro100_init [eepro100]
e00390c0 st_template [st]
e002104c RDINDOOR [megaraid]
e00210a4 callDone [megaraid]
e00226cc megaraid_detect [megaraid] |
The second column refers to the name of a kernel function, and the
first column lists the memory address of that function in the
kernel. The last column reveals the name of the module loaded to
provide that function.
This file provides a look at load average, or the utilization of the
processor, over time, as well as giving additional data used by
uptime and other commands. A sample
loadavg file looks similar to this:
0.20 0.18 0.12 1/80 11206 |
The first three columns measure CPU utilization of the last 1, 5,
and 10 minute periods. The fourth column shows the number of
currently running processes and the total number of processes. The
last column displays the last process ID used.
This files displays the files currently locked by the kernel. The
content of this file contains kernel internal debugging data and can
vary greatly, depending on the use of the system. A sample
locks file of a very lightly loaded system looks
similar to this:
1: FLOCK ADVISORY WRITE 807 03:05:308731 0 EOF c2a260c0 c025aa48 c2a26120
2: POSIX ADVISORY WRITE 708 03:05:308720 0 EOF c2a2611c c2a260c4 c025aa48 |
Each lock is assigned a unique number at the beginning of each
line. The second column refers to the class of lock used, with
FLOCK signifying the older-style
UNIX file locks from a flock system call and
POSIX representing the newer POSIX
locks from the lockf system call.
The third column can have two
values. ADVISORY means that the lock
does not prevent other people from accessing the data; it only
prevents other attempts to lock
it. MANDATORY means that no other
access to the data is permitted while the lock is held. The fourth
column reveals whether the lock is allowing the holder
READ or
WRITE access to the file, and the
fifth column shows the ID of the process holding the lock.
The sixth column shows the ID of the file being locked, in the format
of
MAJOR-DEVICE:MINOR-DEVICE:INODE-NUMBER.
The seventh column shows the start and end of the file's locked
region. The remaining columns point to internal kernel data structures
used for specialized debugging and can be ignored.
This file contains the current information for multiple-disk, RAID
configurations. If your system does not contain such a
configuration, then your mdstat file will look
similar to this:
Personalities :
read_ahead not set
unused devices: <none> |
Things really do not get interesting unless you have
md devices created and in use. In that case,
you can use mdstat to give you a picture of
what is currently happening with your
mdX devices.
This /proc/mdstat file shows a system with its
md0 configured as a RAID 1 device. It is
currently re-syncing the disks, and the percentage completed and
estimated time remaining can be seen:
Personalities : [linear] [raid1]
read_ahead 1024 sectors
md0: active raid1 sda2[1] sdb2[0] 1943840 blocks [2/2] [UU] resync=1% finish=12.3min
algorithm 2 [3/3] [UUU]
unused devices: <none> |
This is one of the more commonly used /proc
files, as it reports back plenty of valuable information about the
current utilization of RAM on the system. A system with 256MB of RAM
and 384MB of swap space might have a /proc/meminfo
file similar to this one:
total: used: free: shared: buffers: cached:
Mem: 261709824 253407232 8302592 0 120745984 48689152
Swap: 402997248 8192 402989056
MemTotal: 255576 kB
MemFree: 8108 kB
MemShared: 0 kB
Buffers: 117916 kB
Cached: 47548 kB
Active: 135300 kB
Inact_dirty: 29276 kB
Inact_clean: 888 kB
Inact_target: 0 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 255576 kB
LowFree: 8108 kB
SwapTotal: 393552 kB
SwapFree: 393544 kB |
Much of the information here is used by the top
command. In fact, the output of the free command
is even similar in appearance to the contents and structure of
meminfo. By looking directly at
meminfo, more memory details are revealed:
Mem — Displays the
current state of physical RAM in the system, including a full breakdown
of total, used, free, shared, buffered, and cached memory
utilization in bytes.
Swap — Displays the
total, used, and free amounts of swap space, in bytes.
MemTotal — Total amount
of physical RAM, in kilobytes.
MemFree — The amount of
physical RAM, in kilobytes, left unused by the system.
MemShared — Unused with
2.4 and higher kernels but left in for compatibility with earlier
kernel versions.
Buffers — The amount of
physical RAM, in kilobytes, used for file buffers.
Cached — The amount of
physical RAM, in kilobytes, used as cache memory.
Active — The total
amount of buffer or page cache memory, in kilobytes, that is in
active use.
Inact_dirty — The total
amount of buffer or cache pages, in kilobytes, that might be freeable.
Inact_clean — The total
amount of buffer or cache pages in kilobytes that are definitely
free and available.
Inact_target — The net
amount of allocations per second, in kilobytes, averaged over
one minute.
HighTotal and
HighFree — The total and
free amount of memory, respectively, that is not directly mapped
into kernel space. The HighTotal
value can vary based on the type of kernel used.
LowTotal and
LowFree — The total and
free amount of memory, respectively, that is directly mapped
into kernel space. The LowTotal
value can vary based on the type of kernel used.
SwapTotal — The total
amount of swap available, in kilobytes.
SwapFree — The total
amount of swap free, in kilobytes.
This file lists miscellaneous drivers registered on the miscellaneous
major device, which is number 10:
135 rtc
1 psaux
134 apm_bios |
The first column is the minor number of each device, and the second
column shows the driver in use.
This file displays a list of all modules that have been loaded by
the system. Its contents will vary based on the configuration and
use of your system, but it should be organized in a similar manner
to this sample /proc/modules file output:
tulip 38544 1 (autoclean)
ide-cd 26848 0 (autoclean)
cdrom 27232 0 (autoclean) [ide-cd]
autofs 11264 1 (autoclean)
ipchains 38976 0 (unused)
usb-uhci 20720 0 (unused)
usbcore 49664 1 [usb-uhci] |
The first column contains the name of the module. The second column
refers to the memory size of the module, in bytes. The third column
tells you whether the module is currently loaded
(1) or unloaded
(0). The final column states if the
module can unload itself automatically after a period without use
(autoclean) or if it is not being
utilized (unused). Any module with a
line containing a name listed in brackets
([ or
]) tells you that this module depends
upon another module to be present in order to function.
This file provides a quick list of all mounts in use by the system:
/dev/root / ext2 rw 0 0
/proc /proc proc rw 0 0
usbdevfs /proc/bus/usb usbdevfs rw 0 0
/dev/hda1 /boot ext2 rw 0 0
/dev/hda7 /home ext2 rw 0 0
none /dev/pts devpts rw 0 0
automount(pid696) /misc autofs rw 0 0 |
The output found here is similar to contents of
/etc/mtab, except that
/proc/mount can be more current.
The first column specifies the device that is mounted, with the
second column revealing the mountpoint. The third column tells the
filesystem type, and the fourth column tells you if it is mounted
read-only (ro) or read-write
(rw). The fifth and sixth columns are
dummy values designed to match the format used in
/etc/mtab.
This file refers to the current Memory Type Range Registers (MTRRs)
in use with the system. If your system's architecture supports
MTRRs, your mtrr might look something like this:
reg00: base=0x00000000 ( 0MB), size= 64MB: write-back, count=1 |
MTRRs are used with Intel P6 family of processors (Pentium Pro and
higher), and they are used to control processor access to memory
ranges. When using a video card on a PCI or AGP bus, a properly
configured mtrr file can increase performance
over 150%.
Most of the time, this value is properly configured for you. For
more information on MTRRs and manually configuring this file, please
see http://web1.linuxhq.com/kernel/v2.3/doc/mtrr.txt.html.
For very detailed information on the various partitions currently
available to the system,
major minor #blocks name rio rmerge rsect ruse wio wmerge wsect wuse running use aveq
3 0 6297480 hda 103927 109145 1549044 1461980 66873 30417 780568 6041420 0 1689360 7506660
3 1 56196 hda1 299 1995 4588 1300 17 9 52 5450 0 5210 6750
3 2 1 hda2 0 0 0 0 0 0 0 0 0 0 0
3 5 4610623 hda5 95638 62150 1262322 1304320 63580 16715 644512 5399710 0 1614680 6704110
3 6 136521 hda6 6808 22109 231336 148110 2384 13484 127608 485020 0 108750 636310
3 7 1494013 hda7 1182 22891 50798 8250 892 209 8396 151240 0 86990 159490 |
Most of the information here is of little importance to most users,
except for the following lines:
major — The major number
of the device with this partition. The major number in our
example (3) corresponds with
the ide0 device in
/proc/devices, letting us know the kind of
device driver used to interact with that partition.
minor — The minor number
of the device with this partition. This serves to separate the
partitions into different physical devices and relates to the
number at the end of the name of the partition.
#blocks — Lists the
number of physical disk blocks contained in a particular
partition.
name — The name of the
partition.
This file contains a full listing of every PCI device on your
system. Depending on the number of PCI devices you have,
/proc/pci can get rather long. An example from
this file on a basic system looks similar to this:
Bus 0, device 0, function 0:
Host bridge: Intel Corporation 440BX/ZX - 82443BX/ZX Host bridge (rev 3).
Master Capable. Latency=64.
Prefetchable 32 bit memory at 0xe4000000 [0xe7ffffff].
Bus 0, device 1, function 0:
PCI bridge: Intel Corporation 440BX/ZX - 82443BX/ZX AGP bridge (rev 3).
Master Capable. Latency=64. Min Gnt=128.
Bus 0, device 4, function 0:
ISA bridge: Intel Corporation 82371AB PIIX4 ISA (rev 2).
Bus 0, device 4, function 1:
IDE interface: Intel Corporation 82371AB PIIX4 IDE (rev 1).
Master Capable. Latency=32.
I/O at 0xd800 [0xd80f].
Bus 0, device 4, function 2:
USB Controller: Intel Corporation 82371AB PIIX4 USB (rev 1).
IRQ 5.
Master Capable. Latency=32.
I/O at 0xd400 [0xd41f].
Bus 0, device 4, function 3:
Bridge: Intel Corporation 82371AB PIIX4 ACPI (rev 2).
IRQ 9.
Bus 0, device 9, function 0:
Ethernet controller: Lite-On Communications Inc LNE100TX (rev 33).
IRQ 5.
Master Capable. Latency=32.
I/O at 0xd000 [0xd0ff].
Non-prefetchable 32 bit memory at 0xe3000000 [0xe30000ff].
Bus 0, device 12, function 0:
VGA compatible controller: S3 Inc. ViRGE/DX or /GX (rev 1).
IRQ 11.
Master Capable. Latency=32. Min Gnt=4.Max Lat=255.
Non-prefetchable 32 bit memory at 0xdc000000 [0xdfffffff]. |
This output shows a list of all PCI devices, sorted in the order of
bus, device, and function. Beyond providing the name and version of
the device, which is always nice to know when you forget the brand
of your network interface card, this list also gives you detailed
IRQ information so you can quickly look for conflicts.
This file gives information about memory usage on the slab
level. Linux kernels greater than 2.2 use slab
pools to manage memory above the page level. Commonly
used objects have their own slab pools.
The /proc/slabinfo file can be rather long, but it
starts off similar to this:
slabinfo - version: 1.1
kmem_cache 59 78 100 2 2 1
ip_fib_hash 10 113 32 1 1 1
ip_conntrack 0 0 352 0 0 1
urb_priv 0 0 32 0 0 1
uhci_desc 1038 1062 64 18 18 1
clip_arp_cache 0 0 128 0 0 1
ip_mrt_cache 0 0 96 0 0 1
tcp_tw_bucket 0 0 128 0 0 1
tcp_bind_bucket 6 113 32 1 1 1
tcp_open_request 0 0 96 0 0 1
inet_peer_cache 0 0 64 0 0 1
ip_dst_cache 26 40 192 2 2 1 |
The values in this file occur in the following order: cache name,
number of active objects, number of total objects, size of the object,
number of active slabs (blocks) of the objects, total number of slabs
of the objects, and the number of pages per slab.
It should be noted that active in this case
means to be in use. An active object is one that is in use, and an
active slab is one that contains any used objects.
This file keeps track of a variety of different statistics about the
system since it was last restarted. The contents of
/proc/stat, which can be quite long, begins
something like this:
cpu 7361636 3040186 1150480 23431255
cpu0 7361636 3040186 1150480 23431255
page 213089 98198
swap 28914 15951
intr 37566857 34983557 1313 0 4 4 128683 <CONTENT-SNIPPED>
disk_io: (3,0):(171639,103942,1549132,67697,784888)
ctxt 323724291
btime 988921599
processes 14882
kstat.input_fastpath: 0
kstat.input_slowpath: 0
kstat.inputqueue_got_packet: 0
kstat.inputqueue_no_packet: 0 |
Some of the more popular statistics include:
cpu — Measures the number
of jiffies (1/100ths of a second) that
the system has been in user mode, user mode with low priority
(nice), system mode, and the idle task, respectively. The total
for all CPUs is given at the top, and each individual CPU is
listed below with its own statistics.
page — The number of
pages the system has paged in and out from disk.
swap — The number of swap
pages the system has brought in and out.
intr — The number of
interrupts the system has experienced.
btime — The boot time,
measured in the number of seconds since January 1, 1970,
otherwise known as the epoch.
This file measures swap space and its utilization. For a system with
only one swap partition, the output of
/proc/swap may look similar to this:
Filename Type Size Used Priority
/dev/hda6 partition 136512 20024 -1 |
While some of this information can be found in other
/proc files, swap provides
for a very quick snapshot of every swap filename, type of swap
space, and total and used sizes (in kilobytes). The priority column
is useful when multiple swap files are in use, and some of them are
preferred over others, such as if they are on faster hard disks. The
lower the priority, the more likely the swap file will be used.
This file contains information about how long the system has on
since its last restart. The output of
/proc/uptime is quite minimal:
The first number tells you the total number of seconds the system
has been up. The second number tells you how much of that time, also
in seconds, the machine has spent idle.
This files tells you the versions of the Linux kernel and
gcc, as well as the version of Red Hat Linux
installed on the system:
Linux version 2.4.2-2 (root@porky.devel.redhat.com) (gcc version 2.96 20000731
(Red Hat Linux 7.1 2.96-79)) #1 Sun Apr 8 20:41:30 EDT 2001 |
This information is used for a variety of purposes, including
providing the version data at the standard login prompt.
