If we want to check one program on one remote server, we need to know this server’s IP and port number. How to get this program’s port number in the remote server? # netstat -tulpn Remember to run this program with root permission since some programs can only be accessed by root. Answered by harryxiyou.
I need to see what kind of interrupts are handled by which CPU. Please run command: # cat /proc/interrupts or you can execute $ watch -n1 “cat /proc/interrupts” to watch interrupts every 1 second. See   for more details. References:  https://stackoverflow.com/questions/28301875/how-to-observe-interrupts-in-windows-or-linux-ubuntu-14-04  http://www.linuxjournal.com/content/watch-live-interrupts Answered by harryxiyou.
Most time, we need to tune system parameters to achieve better performance but what the general parameters to be tuned in Linux systems. I think you may want to add following parameters to Kernel boot (/etc/default/grub) parameters intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll intel_pstate=disable At the same time, you may also want to shutdown/open Pause Loop Exiting (PLE). […]
How to set one task’s CPU affinity quickly? 1, Get this task’s ID # taskset -pc PID 2, Set this task’s CPU affinity # taskset -c affinity ./task Answered by harryxiyou. There is also another format # taskset -pc affinity pid For example: set process with PID 3783 to CPU 15 # taskset -pc 15 […]
When you use a server with other users, you might want to limit other users’ CPU resources for some specific aims. Cgroup has lots of parameters we can use to control computer resources. For CPU resources, you can tune cpu.shares parameter to limit users’ CPU resources. To be more precise, change directory to /sys/fs/cgroup/cpu/user and […]
It is useful to monitor a server node’s temporary. Among all the sensors’ temperatures, the higher one may be a very important one. How to get the highest temperature from all sensors in a server on Linux? You can use this command to get the the highest temperature from all sensors in a server on […]
Most modern servers or computers have sensors to detect the temperature of various components. On Linux, how to get the CPU core temperatur in command linux? First, make sure the package “lm-sensors” is installed on your Linux and the command sensors works for you. Then, you can use this piece of script to get the […]
Good tutorials on git branching. The “Git Branching” chapter of Pro Git book is the best one that I ever seen: http://git-scm.com/book/en/Git-Branching It deserve the time to study the whole chapter. If you are working with a git server, this chapter is especially useful: http://git-scm.com/book/en/Git-Branching-Remote-Branches Answered by Eric Z Ma.
I have access to different git servers. I have several keys for these servers. How to use different keys for different git servers? Use the .ssh/config file to specify different configuration for different SSH servers used by git: For example: Host git.example.org Port 22111 IdentityFile ~/.ssh/id_rsa.git.example.org Host code.example.org Port 22 IdentityFile ~/.ssh/id_rsa.code.example.org which specifies the […]
In Question2Answer, how to enable Sina Weibo and Tencent QQ account log in? Use the Social Plugin for Sina Weibo and Tencent QQ (in Chinese): http://q2achina.sinaapp.com/blog/archives/22/ The websites to apply for the app: Weibo: http://open.weibo.com/ QQ: http://connect.qq.com/ Answered by Adam.
I find one disk failed on my server which have several ones installed. I know the disk’s name in Linux (e.g. sda, sdb). However, the Linux disk name to SATA port mapping does not follow the same order. Now, I want to find out the failed disks. How to quickly find out them and which […]
We ever discussed fixing ports used by NFSv3 so that it can be easily exported to external networks. For NFSv4.1 or higher, things are much easier. The ports for mountd, statd, and lockd are not required in a pure NFSv4 environment. We have less ports to control or allow for connections. Only port 111 and […]
With a list of servers, it is common that one or more are down or crash. Lots cluster management tools can detect the aliveness of servers. However, it can be easily done with ping with a Bash script. I summarize the script that I used and share it here: check-alive-server.sh. Usage: usage: ./check-alive-server.sh file Each […]
NFS is widely deployed and used even after more than twenty year. NFS is easy to set up and easy to use. This introduces how to set up the NFS server and clients. We use the Fedora system as the example. The tutorial here is for RHEL/CentOS/Fedora and derived Linux OSes. Set up an NFS […]