Hi Ralph, the thread is from April. Some coincidences cannot possibly be coincidences. Yesterday, my Windows 10 VM reported that there was no more space available. From my many external backup drives, I took two and deleted some very old backups, as well as copying a few very old backups from one drive to the other, which still amounted to hundreds of GiB. This went very quickly. Then I started a copy (# cp -ai) of the Windows 10 VM to one of the drives. In about 6 hours, not quite 1/3 has been copied, namely 230.4 G of 736.4 G. Either this SSD is damaged or, and this is my guess, it is connected to the PCIe to SATA converter and that is the culprit. Well, I'll copy everything from the SATA SSD to an NVMe (better not from the SSD, but from the backup drive ;) and then see if I'll replace the SSD and/or the converter. Or I try to get rid of the PCIe to SATA converter completely by replacing some of the around 900 GiB SSDs with way larger SSDs. Regards, Ralf PS: I followed hints from https://bbs.archlinux.org/viewtopic.php?pid=2237153 : $ cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-linux root=/dev/disk/by-label/m1.archlinux ro ipv6.disable=1 kvm.enable_virt_at_load=0 zswap.enabled=0 transparent_hugepage=never