Linux Archives - Heiko's Blog

QEMU 7.2 and Raw Disks

Update January 27, 2023: The issue described below is limited to users of RAW partitions. But there is a workaround. See under “What to do?”

A recent update from QEMU 7.1 to QEMU 7.2 caused my Windows 10 VM to show 100% utilization of the C: drive. Performance of the Windows VM dropped to the bottom – the VM was pretty much unusable.

Users at the VFIO Reddit reported similar issues. However, as it turned out, it seems to affect only storage on LVM raw volumes. In other words, if you have your VM in a qcow file, all should be well.

Kernel 6.0 and VFIO

Kernel 6 not booting with VFIO – workaround

Recently I upgraded to kernel 6.0 on my Manjaro rig, but that didn’t go well. The PC booted but there was no screen output. I was able to ssh into the Manjaro host, though.

Searching for an answer led me to the “Linux Kernel 6 seems to be incompatible with the vfio_pci module needed for PCI passthrough” on Level1Techs. If you go further down the thread, you’ll see how someone posted a working solution “Using the driver_override feature“.

Camera Manufacturers: Please Use Accurate Time Stamps for Image Files

My Canon and Nikon cameras use either the exFAT file system or the (older) FAT file system for image storage on their SD, SDxx, CF, CFexpress or XQD cards. In theory, the exFAT file system supports accurate time stamps up to a precision of 10 milliseconds. The FAT32 file system, in contrast, just offers 2 second accuracy for the modification time, or 10 millisecond for the creation time.

New NTFS Driver in Kernel 5.15

Linux kernel release 5.15 introduced a new NTFS file system driver named NTFS3. This kernel driver was originally developed by Paragon Software as a commercial solution (more about the ntfs3 driver can be found on their FAQ page).

NTFS3 is not to be confused with NTFS-3G, a user space driver that employs the FUSE or “file system in user space” approach. There is a 3rd driver available – simply NTFS – that was shipped as the standard NTFS driver on Linux, but it lacked support for many of the Microsoft NTFS features (like writing to disk). Most of us dealing with NTFS drives have installed and use the NTFS-3G driver.

Why Long Tutorials?

Anyone who follows this website will notice that the tutorials are rather long. In these long tutorials I usually give reference specs, explain basic terms or processes, and expand on the how and why.

I wish I could write short, easy, step by step tutorials titled “GPU passthrough made easy” or the “Quick guide to VFIO bliss”. In fact, there are plenty of those out there in the great Internet. Some of the most popular ones are on Youtube, showing you how to get your Windows gaming VM up and running in no time.

Nvidia And The “hidden state”

No more need to hide the hypervisor

Ever since I started to run a Microsoft Windows VM with GPU passthrough, Nvidia graphics drivers would only support their professional Quadro line of graphics cards in a virtual machine. Ten years ago I bit the bullet and bought an outrageously expensive Nvidia Quadro 2000 GPU. Truth be told – it’s been and still is a great GPU and I currently use it for my Linux host. Back then the Quadro was passed through to a Windows 7 VM running on Xen. It worked great.

Manjaro Linux Kernel 5.10

I was so busy studying, writing, and processing photos that I didn’t touch my Manjaro Linux host for a long long time. Then one day I decided to upgrade my PC from a 5.4 kernel to the most recent LTS or “Long Term Support” Manjaro Linux kernel 5.10.

Manjaro Linux

A look at Manjaro Linux from a VFIO passthrough user perspective – the benefits and downsides of using Manjaro as a Linux host

Last year in April I switched from Linux Mint via a short detour to Pop_OS to Manjaro Linux as my host OS. The reasons I chose Manjaro Linux were its up-to-date kernel and software and its well-rounded selection of software packages. However, the latest and greatest kernel and software can come at a price of being less stable. In this post I like to weigh in the pros and cons for Manjaro Linux and what you might want to consider before jumping on the wagon.

LVM and the Ease of Migrating to a New Drive

Online data relocation to other drives using LVM and pvmove

These days my disks are filling up fast. My current PC holds 7 drives, including 2 NVMe drives. Actually 8 drives as I installed a new HDD today. All of my disks and partitions – with the notable exception of the FAT16 EFI partition for UEFI boot – are using LVM, the Logical Volume Manager.

With the availability of larger drives at reasonable costs, I decided to move some logical volumes (LV) spanning several drives onto one single drive, thus consolidating disks. This one drive will then be mirrored in a RAID-1 configuration for redundancy.

Note: In a multi-drive LVM Logical Volume each drive represents a potential point of failure. Moving the data from multiple drives onto one drive reduces that risk.

Passing Through a Nvidia RTX 2070 Super GPU

Tutorial for passing through a Nvidia RTX graphics card to a Windows 10 virtual machine using a modified VBIOS

Last update: September 14, 2021

Starting with the GeForce 1000 series, vfio passthrough of a Nvidia GPU has become a little more complicated. If, when starting the VM, you get a black screen, chances are you need to pass along a VBIOS file to the VM so the GPU can properly initialize.

This post is about passing through a Nvidia RTX 2070 Super GPU or any other modern Nvidia GPU to a Windows 10 guest.