Showing posts from August, 2018

netstat command not found in CentOS 7 / RHEL 7

Netstat command is tool to check the network configure and activity. The default centos 7 and RHEL 7 not found netstat command. How to use netstat command on Centos 7 and RHEL 7 To find out which package provides "netstat" command. yum provides */netstat Or yum whatprovides */netstat The output screen as below net-tools-2.0-0.22.20131004git.el7.x86_64 : Basic networking tools Repo        : @base Matched from: Filename    : /bin/netstat Install netstat command # yum install net-tools The output screen as below: Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile  * base:  * epel:  * extras:  * updates: Resolving Dependencies --> Running transaction check ---> Package net-tools.x86_64 0:2.0-0.22.20131004git.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================

Linux commands cheat sheet

System Commands Command Description Examples shutdown bring your system down shutdown -h now --> Halt or poweroff after shutdown shutdown -r now --> Reboot after shutdown halt stop your system. halt reboot reboot your system. reboot uptime Tell how long the system has been running. uptime runlevel find the previous and current system runlevel. runlevel printenv print all or part of environment printenv env run a program in a modified environment env hostname show or set the system's your host name hostname --> show the system's host name hostname newhostname -->- set the system's uname print system information uname -a --> print all information locale Displays information about the current locale, or

zimbra notify password expired by bash script

In this tutorial, How to remind USER notify passowrd expired on zimbra . Bash script have policy 120 days password expired. zimbra notify password expired by bash script To create zimbra_notify_change file to notify password expired for all zimbra accounts. [root@mail ~]# cat The content zimbra notify password expired as below #!/bin/bash # Bash scriptzimbra password expiry email notification. # To be performed as daily cronjob run as zimbra USER. ######################### Set environment ######################### #Todays date, in seconds: DATE=$(date +%s) # Set some vars: # First notification in days, then last warning: FIRST="7" LAST="3" # pass expiry in days POLICY="120" # Sent from: FROM="[email protected]" # Get all _USERs - it should run once only. _USERS=$(/opt/zimbra/bin/zmprov -l gaa | egrep -v "spam|ham|virus-quarantine|galsync"); # zimbra password variable

Recover Data from Crashed Disks with ddrescue command

How to save and recover Data from Crashed Disks with ddrescue command? This is program is useful to rescue data in case I/O error. How to solve problem “wrong fs type, bad option, bad superblock” error? mount: wrong fs type, bad option, bad superblock on, missing codepage or helper program, or other error (for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> helper program)  In some cases useful info is found in syslog - try dmesg | tail or so. My server OS: Centos 7 HDD1: /dev/sda1 HDD2: /dev/sdb1 ( mount point /mnt) HDD2: /dev/sdb1 is crash, not mount pint /mnt. How to do it! I attach a new HDD3 disk: /dev/sdc1 on my system. use ddrescue command. Install ddrescue on centos # yum install ddrescue How do I use ddrescue command rescue a partition in /dev/sdb1 to /dev/sdc1 ## is damaged, you will need to recreate it somehow on /dev/sdb. ## ddrescue -f -n /dev/sdb /dev/sdc logfile ddrescue -d -f -r3 /dev/sdb /dev/s

Zimbra Enable PTR/Reverse DNS lookup Incomming Email

A reverse DNS lookup or reverse DNS resolution (rDNS) is the querying of the Domain Name System (DNS) to determine the domain name associated with an IP address – the reverse of the usual "forward" DNS lookup of an IP address from a domain name. Zimbra tips, How to Enable PTR/Reverse DNS lookup Incomming Email. More information from Wikipedia . Step 1: Enable zimbraMtaRestriction as command below su - zimbra zmprov mcf +zimbraMtaRestriction "reject_unknown_client_hostname" Step 2: zimbra postfix reload postfix reload Conclusion Thought the article, you can use "Zimbra Enable PTR/Reverse DNS lookup Incomming Email" as above . I hope will this your helpful.

How to using NGINX Multiple ssl certificates on one ip

I experienced setup and configure nginx multiple domain on one VPS. In this tutorial, How to using NGINX Multiple ssl certificates on one ip. Multiple SSL Certificates use letsencrypt Web server: Nginx Two domain: IP VPS: You buy VPS linux and configure multiple domain on one ip VPS server. I use VPS cheap 5 USD/month. I love it! Nginx Redirect all HTTP requests to HTTPS server {         listen 80;         listen [::]:80 ipv6only=on;         if ($host = {         return 301 https://$host$request_uri;         }         if ($host = {         return 301 https://$host$request_uri;         }         server_name;         return 444; } Nginx config for server {         listen 443 ssl http2;         listen [::]:443 ssl http2;         server_name;         root /path/to/do