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.

Nikon Z7 II Review

Half a year ago I replaced my Canon R5 and RF lenses for the Nikon Z7 II and some selected Z mount lenses. Both mirrorless cameras feature a 45 MP sensor, weather sealing, and are in many ways comparable. But a closer look shows substantial differences between both cameras and lenses.

Dome of the Rock with Dome of the Chain, Jerusalem – Nikon Z7 II and Z 14-24 f/2.8 lens (click to enlarge)

This Nikon Z7 II review attempts to not only show the pros and cons of the camera and the lenses I own or used, but I feel also able to compare it with the Canon R5 and some Canon lenses. I will also share some impressions on how the Nikon Z7 II works with the FTZ-II adapter and the Nikon 200-500mm/f5.6 F mount lens.

Canon: Why Make Shutter Count Inaccessible?

Yesterday I finally decided to part with my Canon gear. I tried everything to make it work but it doesn’t work for me. See my Canon EOS R5 Disappointment post.

So, the first thing I thought a potential buyer of a camera might want to know is the shutter count. It is kind of the milage of the camera. Mechanical shutters have a maximum life expectancy that is published by the camera manufacturer. My Canon EOS R5 has an impressive shutter life of 500,000 actuations. That is a lot even for a professional camera body. Compare that to the shutter rating of the Nikon D850 with a mere 200,000 shutter actuations.

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.

Nikon D850 Review

Last edited: February 21, 2022

Edit December 19, 2022: See also my latest Nikon Z7 II Review!

Two and half years ago I wrote a Nikon D700 Review (and D850 Preview) that – for most potential buyers – came a little late. The D700 was long taken off the shelves, replaced by newer models. This time I try to be a little faster and post my Nikon D850 review when this camera is still sold.

Klausenpass, Switzerland – Nikon D850 with Tamron 15-30mm f/2.8 G2 @ 18mm, 1/100s, f10

Canon EOS R5 Disappointment

Updated on December 19, 2022

See also my latest Nikon Z7 II Review for a comparison!

In March 2021 I did it: I bought a new camera, and it wasn’t a Nikon! Not that I never owned other cameras. I’m loyal to my wife, not to my camera gear.

I was looking for a way to reduce weight when hiking. At first I bought a Nikon Z6 II and lenses but wasn’t happy with the focus system and switching between rear display and EVF. While on a hike I missed a good opportunity to shoot low flying eagles because of these two issues. To be fair, I had the “cheap” 24-200mm lens mounted, not some top glass. And I had practically no hands-on experience with that camera. Within a few days I returned the equipment and – after all the recommendations, positive reviews as well as out of curiosity – I jumped to the “other” side: I bought the Canon EOS R5 and an assortment of lenses.

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

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.