Identify virtual machine technology

virt-what is a shell script which can be used to detect if the program is running in a virtual machine.

apropos

apropos is a linux command that search manual pages and descriptions. Example root@mil-146068:~# apropos vagrant vagrant (1) – Tool for

bind

bind is a DNS server. To check bind configuration for errors, run named-checkconf -z /etc/named.conf if chroot named-checkconf -z -t

Install rsync in freebsd from source

On the server, i want to install rsync have no ports as it was older version FreeBSD 5.4 and is

maximum number of open files and file descriptors in linux

To see open files in linux use the command lsof There is a limit set in the kernel on how

lighttpd too many open files

lighttpd server crashes with fllowing error in error_log file. 2019-11-05 09:39:02: (network_linux_sendfile.c.143) open failed: Too many open files 2019-11-05 09:39:02:

df not showing all mounts

On a server, df not showing all mounts root@server20 [~]# df -h Filesystem Size Used Avail Use% Mounted on tmpfs

Show disk usage with df

df command shows partitions and disks used by each partition. root@server54 [~]# df -h Filesystem Size Used Avail Use% Mounted

RHCSA Study Guide

1. Logical volume ‘home’ as created and mounted. Reduce its size to ‘192M’ (size from 185M to 200MB is acceptable)

MySQL ERROR Access denied you need SUPER privilege for this operation

WHen restoring a MySQL database, i get following error root@ns3043014:~# mysql -u NEW_DB_USER -p’PASSOWRD_HERE’ DB_NAME < BACKUP_FILE.sql ERROR 1227 (42000)

debconf: unable to initialize frontend: Dialog

When installing a program in Ubuntu 18.04 server minimal installation, i get following error debconf: unable to initialize frontend: Dialog

Install Unbound DNS caching server

Unbound is an Open source DNS caching and recursive resolver. You can find more about unbound at https://nlnetlabs.nl/projects/unbound/about/ To install