Changing LUKS Passphrase

In my previous blog post, Managing File System Encryption with LUKS, I showed how to create an encrypted partition (of disk) using LUKS. Today, I’d like to show you how we can change the passphrase on this LUKS encrypted partition and keeping this passphrase (key) in the same slot. While I’m writing this blog post, I cannot remember how to do this, and I’m going to try to figure this out without doing the Google search....

July 12, 2020 · 7 min · 1319 words · kenno

Managing Security Risk on RHEL 8

This blog post is mainly about my practicing of managing security risk on a RHEL system, especially learning how to use the occasionally option passed to YUM command. It is probably not a good resource teaching how to properly manage security risks in general. Identify all critical, important, and moderate security notices on this server. [root@puppet2 ~]# yum updateinfo --security Updating Subscription Management repositories. Red Hat Enterprise Linux 8 for x86_64 - Supplementary (RPMs) 21 kB/s | 2....

June 30, 2020 · 3 min · 540 words · kenno

Managing File System Encryption with LUKS

Last year, I already wrote a blog post about the same topic: Configure Encrypted Storage With LUKS, and I had used fdisk to create a disk partition. In this post, I’ll use parted to achieve the same thing. I’m going to perform this operation on a server called servera on a disk device /dev/vdb. First, let’s verify that vdb is available and has no partition: [root@servera ~]# parted -l ... Error: /dev/vdb: unrecognised disk label Model: Virtio Block Device (virtblk) Disk /dev/vdb: 1074MB Sector size (logical/physical): 512B/512B Partition Table: unknown Disk Flags: Use parted to create a partition on vdb using the whole disk....

June 28, 2020 · 3 min · 502 words · kenno

CTDB Not Starting Up on CentOS 7

While preparing for my Red Hat Gluster Storage Administration exam (EX236), I got stuck at a section of configuring IP failover with CTDB Clustered Trivial Database) for Samba. The problem is that I coudldn’t get the ctdb service running on my home lab running CentOS 7 and a newer version of ctdb. This problem occurs on the following platform and package version: CentOS Linux release 7.7.1908 (Core) ctdb 4.9.1-6.el7 # systemctl status ctdb ● ctdb....

October 13, 2019 · 3 min · 513 words · kenno

Configure Encrypted Storage With LUKS

I’m currently preparing for the Red Hat Certified Specialist in Security: Linux exam (EX415). One of the exam objectives is about storage encryption using LUKS. Here’s my note learning about LUKS. It’s not meant to be a guide which you should copy and paste and run it on your production system. Suppose I have a new disk (/dev/vdb) attached to my server and I’d like to use it as an encrypted storage using LUKS....

August 29, 2019 · 3 min · 436 words · kenno