If you changed the hostname/FQDN of a Linux server, you may end up with some issues, especially with mailing if some areas were forgotten with that change. Here is a quick procedure involving all the steps you should be looking for. (The following example is based on a Debian Linux system running Postfix MTA.) 1.… Read More »
OpenVPN enforce by default a 15 minutes lockout policy for unsuccessful login attempts. As an avid system administrator and used to end-user struggles, you most likely encountered many times situations where a user tried to log in 20 times and blaming you that it isn’t working (all that because they are entering the wrong password,… Read More »
Having the following login error attempting to establish a RDP session to a Windows server or workstation? The requested session access is denied. The following behavior apply to your case: The user you are using is a part of the Remote Desktop Users group (or allowed to the RDP users) The user is a non-administrator… Read More »
By default, OpenVPN has 15 minutes timeout lockout policy for consecutive unsuccessful authentication attempt (whatever you are using Local, PAM or LDAP authentication). If you want to change it to shorter or longer time period, follow these easy steps below : 1. Push the new timeout value to the configuration using this command (this example… Read More »
Experiencing the following error loading a Web site hosted on your cPanel server? 503 Service Unavailable And observing the following errors in the Apache logs : [proxy_fcgi:error] [pid 00000] [client 0.0.0.0:42284] AH01079: failed to make connection to backend: httpd-UDS [proxy:error] [pid 00000] (2)No such file or directory: AH02454: FCGI: attempt to connect to Unix domain… Read More »
Outgoing e-mail failing with the following error on your cPanel mail server? 503 Valid RCPT command must precede DATA This can be caused by various factors, such as permission issues, out of space or inode limit reached. To investigate this issue, a good start would be having a look at the logs to find out… Read More »
Heading toward OpenNMS and Grafana for your monitoring and visualization needs? Way to go! (or Oh Yeah! like Duffman would say). First of all, I suppose since you’ve end up reading that post, that you have a successful installation of OpenNMS, Grafana and OpenNMS Help plugin. Adding a data source in Grafana in your OpenNMS… Read More »
If you have an Intel card and the necessary “Advanced Network Services (ANS)”, that is bundled with the Intel driver, you have the capability to manage VLans for your network interface with PowerShell. 1. Use the “ipconfig” command to find out the name of your adapter. Example : PS C:\WINDOWS\system32> ipconfig Windows IP Configuration Ethernet… Read More »
Experiencing the following behavior with RHEL/CentOS 7.2 and NFS? NFS folder mount hang and the following output can be observed in logs and dmesg : NFS: state manager: lease expired failed on NFSv4 server 0.0.0.0 with error 10082 NFS: nfs4_discover_server_trunking unhandled error -512. Exiting with error EIO nfsd: last server has exited, flushing export cache… Read More »
In some rare occasion, you may end up with an orphaned VM in your vCenter inventory where no “remove” option is available from the option menu. Beside doing the removal using the CLI, there is still a way that worked most of the time for me. 1. Browse to “VMs and Templates inventory” inside the… Read More »