5 Great Linux Disk IO monitoring tools Below you see my favorite best 5 Linux Disk IO Monitoring Tools. IOTOP iotop Linux is a simple top-like disk I/O monitor tool. iotop command watches I/O usage information output by the… Continue Reading
After installing sysstat package and running sar command you may have error message: “Cannot open /var/log/sysstat/sa18: No such file or directory. Please check if data collecting is enabled”. I will show how to fix that error on Ubuntu and CentOS… Continue Reading
How To Reset Openfire Admin Password If you forgot Openfire admin password this tutorial will help you step by step Reset Openfire admin password from Linux command line. 1. Stop Openfire Stop Openfire service by command: # service openfire… Continue Reading
How To Exclude Specific Packages from Yum Update in CentOS / RHEL Below I will show some examples how to exclude specific packages updates from manual yum update in Red Hat or CentOS. Yum is the primary tool for… Continue Reading
How To Enable Root SSH On Ubuntu and CentOS By default on Ubuntu server root SSH disabled for security reasons. That means you can login as user then use sudo to became root. In this article I will show… Continue Reading
5 Great Commands to Monitor Network Bandwidth on Linux Server Linux network traffic monitoring is one of the main parts of Linux troubleshooting. And can be done by many network monitoring utilities. In this article we will discover 5… Continue Reading
Docker Tutorial. Create Docker Image From Dockerfile In this docker tutorial I will show simple example how to create docker image from Dockerfile step by step. Also I will how build docker image from scratch. If Docker already installed… Continue Reading
6 Linux lsblk Command Examples lsblk useful terminal command for analysis Linux storage devices. lsblk – LiSt BLocK devices. Linux lsblk command lists information about all available or the specified block devices – disks. The lsblk command reads the… Continue Reading
Zimbra. Postfix_rbl_override.lmdb: No such file or directory How to fix Zimbra mail server error: lmdb:/opt/zimbra/conf/postfix_rbl_override is unavailable. open database /opt/zimbra/conf/postfix_rbl_override.lmdb: No such file or directory. To build missing postfix_rbl_override.lmdb file run postmap and zmprov. # /opt/zimbra/common/sbin/postmap /opt/zimbra/conf/postfix_rbl_override # /opt/zimbra/bin/zmprov mcf… Continue Reading
Useful Netcat Examples In this netcat tutorial you can see useful netcat examples to help you use this powerful tool. Netcat (nc – in short) can be called “Swiss army of knife” in Linux network terminal utilities. Netcat can be… Continue Reading