On Ubuntu 20.04 after installing the NVIDIA driver 510 metapackage the system stopped booting. It will either hang with a black screen and blinking cursor on the top left or show the following error message: Attempting to revert from a snapshot ends up with the same error message. This wasn’t…
Raspberry Pi : Configuring a Time Capsule/Backintime server
In this post, I am setting up a Time Capsule and Backintime server. I am using a Raspberry Pi that has Ubuntu installed, with a USB disk that has been configured into a ZFS pool. Setting up backup users You are going to have to create users for each of…
ZFS: Setting up ZFS storage on Ubuntu
If you are new to ZFS, I would advise doing a little bit of research first to understand the fundamentals. Jim Salter’s articles on storage and ZFS are very recommended. https://arstechnica.com/information-technology/2020/05/zfs-101-understanding-zfs-storage-and-performance/ The examples below are to create a pool from a single disk, with separate datasets used for network backups.…
Linux / Ubuntu / hdparm: Identifying drive features and setting sleep patterns
Preparing the storage Install hdparm and smartmontools Install hdparm and the SMART monitoring tools. Identify the right hard drive Make sure you identify the correct drive, as some of the commands will destroy data. If you don’t understand the commands, then check them first. You have been warned. Identify the…
SNFS/Xsan: Quantum SNFS metadata controller and Xsan client compatibility chart
In a previous life, I designed and built many SANs based on Xsan (I believe I started with Xsan 1.3). I then migrated to looking after SANs based on SNFS, either from 3rd party vendors, or Quantum. I believe that the age of Fibre Channel is long over (although SNFS…
VirtualBox/KVM: Reduce VM sizes
There are two utilities that can help discard unused blocks so that VMs can be shrunk. zerofree finds unused blocks with non-zero content in ext2, ext3 and ext4 filesystems and fills them with zeros. The volume can’ be mounted which makes the process of running it a bit convoluted. fstrim…
Ubuntu: ZFS bpool is full and not running snapshots during apt updates
When running apt to update my system I kept seeing a message saying that bpool had less than 20% space free and that the automatic snapshotting would not run. What I didn’t realise is that this would apply to the rpool even if it had plenty of free space. They…
Ubuntu 20.04: Install Ubuntu with ZFS and encryption
Ubuntu 20.04 offers installing ZFS as the default filesystem. This has lots of advantages. My favourite is being able to revert the system and home partitions (simultaneously or individually) to a previous state through the boot menu. One major drawback for me is the lack of an option to encrypt…
SNFS/Xsan: Changing a volume name
In the past it used to be a very straightforward process. You would rename the volume configuration file and run cvfsck. With newer versions if you try to do that you will get an error message. To make the name change you can use the cvupdatefs command. If you have…
