Difference between revisions of "ProcFS"

Revision as of 13:03, 16 October 2006

Information abaut the current runtime conditions can be found inside the /proc directory. The very most information is read-only. Because it usually is world-readable you do not have to gain root access to look at this information. Files explained on this page are:

/proc/virtual
 .../info

/proc/virtual/<id>
 .../info
 .../status
 .../sched
 .../cvirt
 .../cacct
 .../limit

Per Host

Regarding the host system there is only one file present:

info

/proc/virtual/info
VCIVersion:     0002:0002
VCISyscall:     236
VCIKernel:      03000016

You may compare this info to the output of "vserver-info"; you will recognize two of those entries under a slightly different name while VCIKernel seems to be missing:

x2:~# vserver-info
Versions:
                  Kernel: 2.6.17-2-vserver-amd64
                  VS-API: 0x00020002
            util-vserver: 0.30.210; Sep 30 2006, 23:55:41
Features:
                      CC: gcc, gcc (GCC) 4.1.2 20060928 (prerelease) (Debian 4.1.1-15)
                     CXX: g++, g++ (GCC) 4.1.2 20060928 (prerelease) (Debian 4.1.1-15)
                CPPFLAGS: 
                  CFLAGS: '-Wall -g  -O2 -std=c99 -Wall -pedantic -W -funit-at-a-time'
                CXXFLAGS: '-g -O2 -ansi -Wall -pedantic -W -fmessage-length=0 -funit-at-a-time'
              build/host: x86_64-pc-linux-gnu/x86_64-pc-linux-gnu
            Use dietlibc: yes
      Build C++ programs: yes
      Build C99 programs: yes
          Available APIs: compat,v11,fscompat,v13,net,oldproc,olduts
           ext2fs Source: e2fsprogs
   syscall(2) invocation: alternative
     vserver(2) syscall#: 236/glibc

Per vserver instance

info

This shows the context id, vx_info location and init pid

/proc/virtual/<id>/info 
ID:	1001
Info:	83c37000
Init:	0

status

This contains the usage count (references) and task count, as well as the context flags, capability boundary and context capabilities

/proc/virtual/<id>/status 
UseCnt:	38
Tasks:	16
Flags:	0000000000000000
BCaps:	00000000d46c04ff
CCaps:	0000000000000000
Ticks:	0

sched

Shows the current amount of tokens, scheduler parameters (fill rate, interval, min/max), the priority bias and the calculated vavavoom (priority bonus)

/proc/virtual/<id>/sched 
Token:		       0
FillRate:	       1
Interval:	       4
TokensMin:	       6
TokensMax:	      50
PrioBias:	       0
VaVaVoom:	       0
cpu 0: 0 0 0

cacct

This one accounts socket messages for the listed protocols, as incoming messages/bytes and outgoing messages/bytes

/proc/virtual/<id>/cacct 
UNSPEC:	   	   0/0           	           0/0           	           0/0           
UNIX:	          35/2375        	          35/2375        	           0/0           
INET:	          12/531         	          56/1937        	          57/1705        
INET6:	           0/0           	           0/0           	           0/0           
OTHER:	           0/0           	           0/0           	           0/0           
forks:	0

cvirt

This contains the uptime bias, utsname settings (sys, node, rel, vers, machine, domain), the number of threads, thread stats (running, uninterruptible, on hold), the number of load updates, the load averages (1,5,15) and the number of forks

/proc/virtual/<id>/cvirt 
BiasUptime:	49.73
SysName:	Linux
NodeName:	XXXX.test.org
Release:	2.6.11-rc5
Version:	#12 Sun Feb 27 01:07:29 CET 2005
Machine:	i686
DomainName:	
nr_threads:	16
nr_running:	0
nr_unintr:	0
nr_onhold:	0
load_updates:	14585
loadavg:	0.00 0.00 0.00
total_forks:	272

limit

Limit columns are: current (1), max observed (2), limit (3) and number of hits (4)

Limit rows are: processes, virtual memory, locked memory, resident set size, anonymous memory, number of files, filedescriptors, locks, sockets, message queues, and shared memory

/proc/virtual/<id>/limit 
PROC:	        16	        17	        -1	     0
VM:	     14440	     15331	        -1	     0
VML:	         0	         0	        -1	     0
RSS:	      5478	      5847	        -1	     0
ANON:	      1516	      1516	        -1	     0
FILES:	       140	       155	        -1	     0
OFD:	       122	       122	        -1	     0
LOCKS:	         1	         3	        -1	     0
SOCK:	         9	         9	        -1	     0
MSGQ:	         0	         0	        -1	     0
SHM:	         0	         0	        -1	     0

Debugging Control

This complete directory seems not to be present by default. Possibly there is a compile- or a runtime-switch to enable debugging.

/proc/sys/vserver
  .../debug_switch
  .../debug_xid
  .../debug_cvirt
  .../debug_limit
  .../debug_dlim
  .../debug_nid
  .../debug_net
/proc/sys/vserver/debug_switch
/proc/sys/vserver/debug_xid
/proc/sys/vserver/debug_cvirt
/proc/sys/vserver/debug_limit
/proc/sys/vserver/debug_dlim
/proc/sys/vserver/debug_nid
/proc/sys/vserver/debug_net

If the directory exist you should be able to create these files by issuing commands like:

echo 255 >/proc/sys/vserver/debug_switch

The bigger problem is to find out which values are useful, see Debugging for details.

Please note: some samples are simply copied from the old wiki at http://oldwiki.linux-vserver.org/HowTo+Read+ProcFS, some other are captured from an Athlon AMD X2 system. They do not necessarily fit together.