After one of the recent updates, a few KVM-based systems could not boot anymore. I am using ZFS for my emulated block devices, and I was happy with that until recently. Now – VMs won’t start, showing the error message in this post’s header. The source of the problem is rather nasty – qemu update…
This is a bit on the less legit side, but a need rose where I was required to update the BIOS on an old SuperMicro SBB server. The thing is – the IPMI, which is fully capable otherwise, did not allow me to update the BIOS using this interface, and the other options were using…
Hi. As some know now, I have an article about encrypting and protecting Linux – while using TPM to prevent the need to enter the encryption passphrase every time the system boots. This is one of the most popular article in this blog, and for a very good reason – people want their computers (especially…
Diving videos tend to be blueish. There are tools to automatically fix it, or at least – enhance the video so that the colours appear more natural. Unfortunately, most of these tools either don’t work well with Linux, or with my phone. After a short investigation, I was able to produce a satisfactory result with…
The IO scheduler blk_mq was designed to increase disk performance – better IOps and lower latency – on flash disk systems, with emphasis on NVME devices. A nice by-product, is that it increases performance on the “older” SCSI/SAS/SATA layer as well, when the disks in the back are SSD, and even when they are rotational…
Every Linux admin is familiar with the long time running through a large directory tree (with hundred of thousands of files and more) can take. Most are aware that if you re-run the same run-through, it will be shorter. This is caused by a short-valid filesystem cache, where the memory is allocated to other tasks,…
