Posts

Today, one of my VMs needs to have its disk increased. I’m using qcow2 as the VM’s storage. Here is one way to expand the storage that it’s been proven to work very well for me. I already increased this VM’s disk to 30GiB once already, but it wasn’t enough. So here, let’s explode it to 50GiB. The name of the qcow2 file is hosta.qcow2. A friendly reminder that you should alway shave a backup before you perform any critical change such as this one. (I use ZFS, so all I had to do was snapshoting this whole dataset.) ...

One of the requirements to join an Identity Management Server (IdM) to an Active Directory (AD), a DNS delegation needs to be created on AD. With the Red Hat training for RH362, we were taught to use a command-line interface program called dnscmd on AD server. I personally found this command very cumbersome, and I think a better way is to do this DNS delegation using PowerShell cmdlet. I’ll demonstrate how to do DNS delegation both using dnscmd and PowerShell cmdlet. You can decide yourself which one you find easier to use. ...

Today I passed the Red Hat Identity Management exa, EX362, with the score of 233/300. The material used to prepare for the exam is the RH362 online course, provided Red Hat. At first I wasn’t sure if I should use of the 5 exam credits (as part of one-year training subscription), but it turned out that IdM/FreeIPA is useful and fun to learn. Here are some tips for this exam: ...

I’m a fan of ZFS filesystem. It’s so good that I also use ZFS on most my Linux machines, though it’s painful at time when the ZFS kernel modules fail to compile. Why I like it so much comparing to other file system such as XFS, EXT4, BTRFS? ZFS allows me to quickly do snapshots and efficiently send snapshots over the network, and my nas runs FreeBSD which support ZFS natively. ...

You’ve been using Linux for a while, so you must have seen or used this command before: cat. It’s used to concatenate files and print on the standard output. But do you know there is another command spelled it reversed tac? tac is like cat, but print files in reverse. Here is an example which cat could be handy. I need to print out the last login user in reverse. (By the default, it prints the last login first.) ...