Categories
Uncategorized

How to downgrade package using yum

Downgrade package using yum.

Categories
Uncategorized

How to download RPM packages

Download RPM packages from YUM repository using additional yum utilities.

Categories
Uncategorized

How to increase Google Cloud virtual machine disk size

Increase Google Cloud virtual machine instance disk size without service interruption.

Categories
SysOps

How to disable Google Accounts daemon

Enforcing your own security policy that defines users, SSH keys, and sudo configuration inside custom templates based on official images in Google Cloud requires that you disable Google Accounts service, so it won’t get in the way.

Categories
Uncategorized

CentOS 6 – _netdev fstab option and netfs service

Yesterday I had a small problem. I have added GlusterFS mount point to the fstab but filesystem wasn’t mounted automatically after I rebooted the operating system (CentOS).

Categories
Uncategorized

How to relay selected mailboxes using ISPConfig 3

I hit an intriguing problem as I needed to relay selected mailboxes rather than the whole domain. I assume that you have already noticed that everything needs to happen on the same domain. It is rare and quite interesting task so I will quickly describe it here using ISPConfig 3 but beware as this is a very specific topic so I strongly suggest to investigate it further before applying any changes.

Categories
Uncategorized

CentOS 6 – RepoForge and Advanced Policy Firewall

Hmm… Today I hit funny problem as I couldn’t install Advanced Policy Firewall from RepoForge (RPMforge) repository on CentOS 6. Fortunately the solution is trivial and doesn’t require any magic…

Categories
Uncategorized

Brief note on the MySQL Master-Slave replication

What to do when you want to analyze data contained in database without overloading the server? The answer is simple as you can use MySQL Master-Slave replication to offload this task. I will describe it briefly here.

Categories
Uncategorized

CentOS netinstall – Mirror URL

Couple days ago I decided to use netinstall CD to install CentOS but got somewhat surprised by the “URL Setup” step as I didn’t expect to enter full URL containing installation image.

Categories
Uncategorized

CentOS – fping 3.3 plus Smokeping 2.6.8 equals to empty graphs

fping was updated last month (2012-08-19) to version 3.3. Output statistics were directed to stdout instead of stderr so Smokeping (2.6.8) was not updating RRD files as a result.