Find out the number of CPU cores on Linux
How to find out the number of CPU cores on a Linux host.
Use the command nproc
.
$ nproc
nproc – print the number of processing units available: man page of nproc.
How to find out the number of CPU cores on a Linux host.
Use the command nproc
.
$ nproc
nproc – print the number of processing units available: man page of nproc.
It is common to convert a string (std::string) to integer (int) in C++ programs. Because of the long history of C++ which has several versions with extended libraries and supports almost all C standard library functions, there are many ways to convert a string to int in C++. This post introduces how to convert a…
MediaWiki is the wiki-engine that runs Wikipedia. In this tutorial, we introduce how to configure search engine friendly URLs in MediaWiki. ==Search Engine Friendly URLs== Default MediaWiki URLs look like www.example.com/w/index.php?title=TITLE which is a little ugly. To make it more search engine friendly, we will change it to SEO-friendly URLs like www.example.com/w/TITLE. ==Enabling Search Engine…
Introduction In general, if we want to debug Linux Kernel, there are lots of tools such as Linux Perf, Kprobe, BCC, Ktap, etc, and we can also write kernel modules, proc subsystems or system calls for some specific debugging aims. However, if we have to instrument kernel to achieve our goals, usually we would not…
In C, how to get the hostname of the node? In C, you may use the gethostname function. #include <unistd.h> int gethostname(char *name, size_t namelen); The gethostname() function shall return the standard host name for the current machine. The namelen argument shall specify the size of the array pointed to by the name argument. The…
We have a running HDFS cluster. Currently, the NameNode metadata data directory has only one directory configured in hdfs-site.xml: <property> <name>dfs.namenode.name.dir</name> <value>file:///home/hadoop/hdfs/</value> <description>NameNode directory for namespace and transaction logs storage.</description> </property> We would like to add a new directory for dfs.namenode.name.dir to make replicas of the metadata on a separated disk for higher data reliability….
This is the scenario: I want to remove a old hard disk which is a LVM PV and contains data. There is free space available on other PVs in the VG. It should move the data from the disk to be removed to other PVs and then remove the disk. The process to remove sdb…