What are popular / good NoSQL databases?
What are the popular / good NoSQL databases nowadays?
MongoDB, CouchDB
Find more at https://en.wikipedia.org/wiki/NoSQL and http://nosql-database.org/
What are the popular / good NoSQL databases nowadays?
MongoDB, CouchDB
Find more at https://en.wikipedia.org/wiki/NoSQL and http://nosql-database.org/
In Golang, the fmt.Println() is convenient to print to STDOUT. But how to print string to STDERR? In Go os package, “Stdin, Stdout, and Stderr are open Files pointing to the standard input, standard output, and standard error file descriptors.” So, you can use the WriteString function on File on os.Stderr to print string to…
How to force a fsck of a file system, say the root, during the next rebooting of Linux? 2 possible ways: /forcefsck way for / # touch /forcefsck and reboot. Next time the / will be fsck’ed . systemd way Add these 2 kernel boot parameters: fsck.mode=force fsck.repair=yes What these 2 kernel parameters do: KERNEL…
Where is MySQL / MariaDB storage location by default on CentOS 7? No special configuration to the MariaDB from official repository of CentOS. On CentOS 7 Linux it is usually by default /var/lib/mysql But here I give you another “hacky” way to find it out. The method is to find out the mysql daemon mysqld’…
Update on Oct. 9, 2014: You should be aware of the possible security problems of blowfish and it is suggested not to be used. Instead, you may consider ChaCha20 as suggested by Tony Arcieri. To use this with OpenSSH, you need to specify the Ciphers in your .ssh/config files as chacha20-poly1305@openssh.com possibly with another default…
How to iterate all dirs and files in a dir in C++? To open a dir, we can use opendir() to open a directory stream. DIR *opendir(const char *name); Then we can use readdir() to iterate the directory stream. struct dirent *readdir(DIR *dirp); Here is an example C++ program using these 2 library functions. #include…
How to find which hard drives a LVM volume uses to decide which volume will be affected if a disk failes. You can use lvdisplay with the –maps option to display the the mapping of logical extents to physical volumes and physical extents: # lvdisplay –maps To map physical extents to logical extents, use #…