How to run an instance of nscd daemon per network namespace? I did the following:
ip netns exec <network_namespace> /usr/sbin/nscd
However, it threw output
/usr/sbin/nscd: already running
The intention for an instance of nscd per namepace is this:
Each network namespace has separate host files (/etc/hosts, /etc/resolv.conf) and modifying these host files should trigger the nscd daemon to clear the nscd cache.
The use-case is as given below:
The user has a Flat File in his Linux system. This file is a human readable/editable file which contains the configurations for all the needed components of his application running on the system. For example, the user has an application 'APP' which has components like 'A' , 'B' and 'C'. and the 'Flat File' is housing the configuration for 'A' , 'B' and 'C' as follows:
A
Parameter1: value1
Parameter2: value2
Parameter3: value3
..
..
B
Parameter1: value1
Parameter2: value2
Parameter3: value3
..
..
C
Parameter1: value1
Parameter2: value2
Parameter3: value3
..
..
The user is expecting a configuration utility to read this file and configure the components A, B and C appropriately using the REST APIs associated with the components when the application starts.
Is the configuration tool like Chef capable of doing the above scenario? Otherwise, recommend any other open source tools capable of doing this.
The SNMP trap always uses the first IP address as displayed in the network adapter binding order on the computer. For example, assume that the computer has the following binding order:
172.30.136.231)192.59.196.178)In this situation, the SNMP trap uses the 172.30.136.231 agent IP address.
Or, assume that the computer has the following binding order:
192.59.196.178)172.30.136.231)In this situation, the SNMP trap uses the 192.59.196.178 agent IP address
Inorder for the SNMP trap to contain the IP address actually connected to the machine as the agent IP address, the workaround is to change the network adapter bind order.
So my questions are :
Following are the some contents of my /etc/syslog-ng/syslog-ng.confrelated to logging in to the file debug.log
source s_sys { file ("/proc/kmsg" log_prefix("kernel: ")); unix-stream ("/dev/log"); internal(); # udp(ip(0.0.0.0) port(514)); };
destination d_mesg { file("/tmp/log/debug.log"); };
filter f_filter2 { level(info..emerg) and not facility(mail,authpriv,cron); };
log { source(s_sys); filter(f_filter2); destination(d_mesg); };
I would like to take your attention towards the line containing "filter". There you can see that i am filtering out the logs from mail, authpriv and cron. As far as my knowledge goes, mail, authpriv and cron are pre-defined facilities of syslog.
My query is :
I have a written a daemon named "pm" which also uses the syslog APIs for logging. Now whatever my daemon logs, goes into the file /tmp/log/debug.log as you can see above. I would like to filter out the logs of "pm" from going into /tmp/log/debug.log. To make it more clear i would like to have the filter like
filter f_filter2 { level(info..emerg) and not facility(mail,authpriv,cron,pm); };
Please Note : the difference in f_filter2 compared to above.
Is it possible to do this ? How can i prevent pm logs from going into /tmp/log/debug.log?
There are several kernel messages printed to the console during boot time. I do not want the messages with loglevel "KERN_WARNING" to printed to the console. I only want the loglevels above "KERN_WARNING" like "KERN_ERR" to be printed to the console during boot time. When and where should i make changes to get this done. Do the changes have to be made during build time of kernel? Where should i make the changes to change the loglevel.?
I am using WindRiver Linux on PowerPC in an embedded environment. The boot loader i am using is uboot.
When i do ps -eaf, i cannot find the klogd daemon as well.
I am running my proprietary application (the name of which I would prefer not to disclose) in Linux 2.6 kernel, running on PowerPC (P2020) in an embedded environment. I am using syslog-ng to collect the logs from my application.
When the system is heavily loaded during the running of the application, it is seen that there is a jump in the timestamps in the log files. ie, No logs in the log files for considerable amount of time.
I have enabled Watchdog hardware to reset the processor if the system hangs due to running the application but no reset of the processor is seen and so it means that the application is running fine. Yet still the time jump occurs when the system is heavily loaded.
Is this a known behavior of syslog-ng? Is there any way to avoid this time jump? Please give me some input or documentation where this problem is already reported and the solution given.
Where can I find the source code for Linux utilities and daemons. Basically I want to know the repository of source codes other than the Linux kernel.
Consider a machine having 4 eth ports running on it. Then to which eth port's ipaddress will the hostname resolve to?
Kindly guide me to some documentation to support your answers so that I could use them as proof in my project.
Thanks
My system reboots when i give the "date -s" command. I collected the log and it says this
Jan 18 13:27:46 watchdog[2421]: file /tmp/cmm/strobeWDT was not changed in 1 seconds.
Jan 18 13:27:46 watchdog[3303]: shutting down the system because of error 2
Jan 18 13:27:47 watchdog[2421]: stopping daemon (5.2)
My application run on the system writes into the file /tmp/cmm/strobeWDT. If it fails to write to the file periodically, the watchdog daemon sends a reboot command. That is understandable. But only when i give the "date -s" command to set a new date, the system logs the above message and reboots.
Where is the problem existing.
I dont know whether the above info is enough to solve the problem from your side. Kindly help
Adding more info
I am getting the above log message from the code in file_stat.c (file inside the source code for watchdog daemon)
file_stat.c
#if USE_SYSLOG
/* do verbose logging */
if (verbose && logtick && ticker == 1)
syslog(LOG_INFO, "file %s was last changed at %s.", file->name, ctime(&buf.st_mtime));
#endif
if (time(NULL) - buf.st_mtime > file->parameter.file.mtime) {
/* file wasn't changed often enough */
#if USE_SYSLOG
syslog(LOG_ERR, "file %s was not changed in %d seconds.", file->name, file->parameter.file.mtime);
#else /* USE_SYSLOG */
fprintf(stderr, "file %s was not changed in %d seconds.", file->name, file->parameter.file.mtime);
#endif /* USE_SYSLOG */
I think problem exits in this part of the code, bcause the the error comes from this code. parameter.file.mtime is configured in /etc/watchdog.conf as "change=1"
When my system boots up it shows the following message.
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: RTNETLINK answers: Invalid argument
[ OK ]
Bringing up interface eth1: RTNETLINK answers: Invalid argument
[ OK ]
Bringing up interface eth2: RTNETLINK answers: Invalid argument
[ OK ]
Bringing up interface eth3: RTNETLINK answers: Invalid argument
[ OK ]
Why is this happening. Normally it does not give the message RTNETLINK answers: Invalid argument
I did ifconfig and the output is
eth0 Link encap:Ethernet HWaddr 00:00:50:6D:56:B4
inet addr:120.0.10.137 Bcast:120.0.255.255 Mask:255.255.255.0
inet6 addr: fe80::200:50ff:fe6d:56b4/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:214 (214.0 b)
Base address:0xa000
eth1 Link encap:Ethernet HWaddr 00:00:50:6D:56:B5
inet addr:121.0.10.137 Bcast:121.0.255.255 Mask:255.255.255.0
inet6 addr: fe80::200:50ff:fe6d:56b5/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:214 (214.0 b)
Base address:0xc000
eth2 Link encap:Ethernet HWaddr 00:00:50:6D:56:B6
inet addr:128.0.10.137 Bcast:128.0.255.255 Mask:255.255.255.0
inet6 addr: fe80::200:50ff:fe6d:56b6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:14 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1006 (1006.0 b) TX bytes:396 (396.0 b)
Interrupt:16
eth3 Link encap:Ethernet HWaddr 00:00:50:6D:56:B7
inet addr:123.0.10.137 Bcast:123.0.255.255 Mask:255.255.255.0
inet6 addr: fe80::200:50ff:fe6d:56b7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:10 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:728 (728.0 b) TX bytes:396 (396.0 b)
Interrupt:17
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:14 errors:0 dropped:0 overruns:0 frame:0
TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:980 (980.0 b) TX bytes:980 (980.0 b)
What could be the reason for the message and how to change this to normal?
Thanks
I have 2 machines running linux.
In one machine, the reboot command is an executable normally found in all linux distributions.
In the second machine the reboot command is a shell script customized using some other hardware tool commands to reboot the system.
One behavior difference between the two machines is that when I execute the reboot command on the first machine, it shows another shell prompt and then reboots.
But in the case of second machine, it reboots without showing a shell prompt. I expect the second machine to behave the same way as first machine when reboot command is given.
Currently I am analyzing the source code of shutdown.c and halt.c normally found in linux distributions, so that I can find out the implementation which produces the shell propmt on reboot and use that in the shell script in second machine.
Kindly give me some pointers on where I should start looking to find the implementation.
Thanks
I have two servers running Linux 2.6.9 kernel.
When i telnet to server1 , the telnet will be disconnected only after 3 login failures. While, when i telnet to server2, telnet will be disconnected after the first login failure. I expect server2 to behave the same way as server1 when telnet is executed.
Kindly tell me where i should tweak my servers so that i could achieve what i expect.
Thanks, LinuxPenseur
Can i open /etc/passwd file using an editor like vi and then add a comment into this file. If i am able to do that, will the change be persistent after reboot. If it is not the right way to edit the file in the above mentioned way, what is the ideal way to do this?
Thanks
In one of my linux machines, when i give reboot command at the shell command prompt then press enter, i get another command prompt and then the system reboots.
$reboot
$
But in one of my office Linux machines, when i give the reboot command, it suddenly reboots without showing another shell command prompt
What could be the reason for this? I need the first behavior to be present in my office machine also. Kindly tell me where i should tweak my office machine.
Thanks
I did the date command and it gave the following output
root@localhost:~$ date
Thu Dec 30 14:19:47 UTC 2010
Then i modified the date using date -s command whichn gave the following output
root@localhost:~$ date -s "12/30/2010 JST 14:19:47"
Thu Dec 30 05:19:47 UTC 2010
I noticed that the time changed to 9 hours behind UTC time to show exactly the JST time. But timezone as you can see is still showing UTC. Why is it showing the correct time and incorrect timezone?
Thanks
I want to run a shell script when date -s <string> command is used. For example i want to log the command to the file /tmp/user.log by executing the following command in the shell script
logger -p user.notice "date -s command executed" -f /tmp/user.log
How can run a shell script when date -s <string> is executed on the shell?
To make it more general, I want to run my shell script when someone else issues a particular linux command on my system. How to do this?
I know that the date -s <STRING> command sets the time described by the string STRING.
What i want is to log the above command whenever it is used to set the time into the file /tmp/log/user.log.
In my Linux distribution the logging is done by syslog-ng. I already have some logs going into /tmp/log/user.log.
This is the content of /etc/syslog-ng/syslog-ng.conf in my system for logging into /tmp/log/user.log
destination d_notice { file("/tmp/log/user.log");};
filter f_filter10 { level(notice) and not facility(mail,authpriv,cron); };
log { source(s_sys); filter(f_filter10); destination(d_notice); };
What should i do so that date -s command is also logged into /tmp/log/user.log
I know that the filename is stored in directories and not in inode. Kindly tell me where the inode number of a file is stored? Is it stored in the directory file?