While doing a distro upgrade with I kept getting failures half-way stating The errors showed several IPv6 addresses that couldn’t be reached. My router supports IPv6, but not my ISP. Somehow I was expecting that the router would be doing the translation or DNS resolution between the two but this…
Ubuntu: apt error message “Key is stored in legacy trusted.gpg keyring”
After upgrading to Ubuntu 22.04 running apt shows an error message saying “Key is stored in legacy trusted.gpg keyring“: The key needs to be exported from the legacy keyring and then imported back to the current system. List the keys and find the key ID of the repository that is…
Linux: Booting in single-user mode
Sometimes it might be necessary to start in single-user mode to do some administration work, or even reset an existing password. Normally this can be achieved via the GRUB boot loader. CentOS / RedHat (with root account enabled) Switch on your system. Press Esc until the GRUB menu shows up.…
ZFS ‘Failed to start Mark current ZSYS boot as successful’ fix
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…
Linux / Unix: Comparing differences between folders
I had to check the file changes between two Backintime snapshots recently. You can always use rsync for that, but there is a more straightforward way by using diff. -q will display only the files that differ. -r will make the comparison recursive. There is a GUI application called Meld…
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…
NTP: Setting up an NTP server
Setting up an NTP server chrony is the default service on newer OS releases (Red Hat 7.2 and later, any recent Ubuntu release). chrony has several advantages over ntpd: Quicker synchronisation. Better response to changes in clock frequency (very useful for VMs). Periodic polling of time servers isn’t required. It…
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…
