A CentOS 7 server running Icinga 2 was recently updated using yum update killed the service. The service simply did not restart. The reason turned out to be quite simple. The resolution is just as simple. According to the Icinga docs, upgrading Icinga 2 is usually quite straightforward. Ordinarily the only manual steps involved are scheme updates for the IDO…
Read More »This article details how to reset a forgotten MariaDB root password. I am not shedding any new light to this, this is here for a quick reference for me. The source of this excellent article is at the bottom of the page. Stop the service and start MariaDB in safe mode. There may be a slight hang, just type mysql…
Read More »While performing yum updates on CentOS 7 minimal install virtual servers, I came across a problem server. The server needed a reboot after performing a hardware change. It did not come back up. It had a Kernel Panic error. I did so many things to that server, I didn’t know what the cause for the panic was, but fortunately I…
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After the much advertised Microsoft deadline of July 29, 2016 for the FREE Windows 10 upgrade had passed, it turns out that there is an extension for Windows 10 free upgrade for customers who use assistive technologies. This upgrade path is still valid as of September 22, 2016, so I thought I would upgrade a Dell i3 laptop from Windows…
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Although it is well documented that the Dell Latitude E6420 supports up to 8GB of RAM. Since memory prices have dropped over time, it was well worth the chance to upgrade the 8GB of RAM to 16GB of RAM. This may not work for everyone, but, it certainly worked on one Dell Latitude E6420 laptop. Using crucial.com the memory scanner…
Read More »There was a time when Microsoft Windows 95 ruled the scene. That time has come to pass a long time ago. However, while going through some 20 year old notes, I came across this little gem to upgrade a system that has Microsoft DOS 6.22 with Microsoft Windows 95 to Microsoft Windows 95B and keep the settings and files in…
Read More »Everyday with Linux there seems to be something new to learn or a little tidbit that is worth remembering. This time, the sysrq. Activates the System Request Key (aka. the Magic SysRq key), if thi value is set to anything other than zero (0), the default. sysrq The System Request Key allows immediate input to the kernel through simple key…
Read More »There are many articles that more than adequately detail a basic installation of the Windows Server Update Services (WSUS). This article assumes two things. The GPO has been configured and that this is a fresh installation of Windows Server 2012 with WSUS installed. No computers have connected yet. This article picks up at this point. Additional updates and configurations were…
Read More »All subversion checkouts, commits and other basic operations work as expected, but when attempting to copy, move or tag (copy) a (502 Bad Gateway) error presents itself. The error may be similar to the one presented below. Setup There is a machine running nginx on port 80 (and 443 SSL) that serves as a reverse proxy for among other things…
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CentOS7 offers a completely different approach to resetting a forgotten root password than the it’s earlier distro of CentOS6.x. Here are multiple approaches that was tested on CentOS Linux release 7.2.1511 (Core) with success. The last one being one that I combined from the many different approaches into fewer steps. Reset the Root password (version 1 Reboot the system to…
Read More »Migrating to newer version of a web application from one domain to another has had it’s challenges. Since this web application has multiple projects, each project may be migrated one at a time. The goal is to redirect traffic to the new projects as they are migrated to the new domain. As part of that goal, the projects that have…
Read More »The man pages describe pdnsd as a dns proxy daemon capable of saving the contents of its DNS cache to the disk on exit. The Install Edit the /etc/pdnsd.conf file. Under server, change the ip value to your DNS server. Edit the /etc/resolv.conf to point the server to itself. For my test, I commented out everything and only added the…
Read More »According to Red Hat, “[t]he Name Service Caching Daemon (nscd) is a service that runs in the background and keeps a copy of /etc/passwd, /etc/group, [/etc/netgroup, /etc/services] and /etc/hosts files in /var/db/nscd/ directory. This can aid performance by reducing disk read overhead on a heavily loaded system dealing with many logins or name resolution requests.” The installation and usage is…
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Working on an early install of CentOS 6 and trying to update the system, the update failed. Even an attempt to update the ca-certificates failed. It turns out that the EPEL repository was the cause of this. To work past the offending EPEL repository and upgrade the ca-certificates, the following command works. Upon completion, a simple, yum update will work….
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To install an alternate version of, in this case, MySQL, rather than to accept the version that is available via the base and update yum repositories for CentOS, there are several ways of going about this. You could install via tar.gz or download RPMs and yum install them directly; however, adding the official MySQL repository will work too. It is…
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Emailreg.org provides the Registered Email Send List (RESL) as a free lookup to anyone that would like to use it. It is also provided to those who have registered a domain here at EmailReg.org. The RESL is provided using a system that is similar to a DNS lookup. It is even more similar to a DNSRBL lookup. The RESL, however,…
Read More »Configure Sendmail email server to use SSL encryption for sending/receiving email. This is an example of using a CA certificate rather than a self-signed certificate. This article assumes that the CA certificate is already in place and ready to go. Modify the /etc/mail/sendmail.mc file. Find the section with similar variables that is commented out and copy this under it. At…
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