Lvm

I recently ran into a classic problem on my long-running Fedora installation: my /boot partition was full. Back when I set up the system (around Fedora 20), 400MiB was more than enough. Now, with modern kernels, it can barely hold two versions, let alone the default three that Fedora manages. This meant I couldn’t run system updates. The challenge was that my disk was partitioned with /dev/sda1 for /boot and /dev/sda2 as a single large LVM physical volume for my /root and /home filesystems. This setup prevents a simple resize of /dev/sda1. ...

Recently, after an OS updated and rebooted, I was not able to login to the desktop environment. When that happened, I thought to myself, “I wish I could just do a quick EBS snapshot like I would on the cloud before running any OS updates.” On my Linux desktop, the root volume is an LVM volume, I knew that snapshot was possible, but never tried to create one before. A friend at work encouraged that I should make use of it, and it was not that hard to get started. Well, let’s see how it goes as I’m about to explore how LVM snapshot works on my desktop. ...

On one of my servers, I used to have a storage device, /dev/sdb, attached to it. That storage was used as an LVM physical volume. It has later been removed, and now I just noticed the following message: [root@banan ~]# lvs Devices file PVID CuDRE3nMN5FMNqYLViHrnE1D7OFDlbX6 last seen on /dev/sdb not found. LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root almalinux -wi-ao---- <28.40g swap almalinux -wi-ao---- 2.01g Based some research found online, there could be outdated device entries in the device files located in /etc/lvm/devices/system.devices. ...

Well, I hardly need to activate or deactivate LVM volume groups. But when I do, I also hardly remember the command required to do that. So hopefully, I can refer to this post should I need to perform one of these tasks in the future. Since a volume group is activated by default when it is created, let’s start with a command to deactivate it. # vgchange -a n example_volume_group Like wise, to activate a volume group, use the following command: ...

I’m quite sure I’d resized qcow2 images before. However, when I needed to resize an image today for my VM at home, I totally forgot about it. Well, this means it’s a good excuse for me to just write down a few commands to help me in the future. If you try to follow a long, two things you wanna keep in in mind: do it at your own risk, and always backup your data before you make change to it. Having said, that’s get started. ...