>> Since version 1.45, os-prober instead uses grub-mount when it's available >> -- and if grub is installed to use os-prober, it will pull it in. > >> So unless another bootloader is also using os-prober, or someone >> installs and uses it by hand, this won't happen in unstable/testing.
> It's not really the case. I agree here with Jean Francois. Here the problematic code in os-probes/common/50mounted-tests line 49, simplified for better understanding if type grub-mount && type grub-probe && grub-mount "$partition" ; etc ... else blockdev --setro done fi the problem here is that when using LVM what 50mounted-tests treats as a $partition might very well be a disk image (512 first bytes will contain a MBR) In that case grub-mount will fail and pass the hand to ro_partition which will be happily set the whole device as read only, causing the file system errors in the guest poking on the idea of Michael I was wondering it would be possible to test before calling blockdev --setro if the block device we target has a file descriptor pointing to it. This would indicate that something/someone is actually doing something with the block device and we should rather leave it alone. in pseudo shell it would look like: if ls -l /proc/*/fd | grep $(realpath $partition); then debug "active file descriptor on $partition) return else blockdev --setro fi I find this a bit hacky however. What we also do would be simply to change the depency on os-prober from "recommends" to "suggests" in os-prober, and add os-prober as a dependency of the desktop task of the debian-installer (which is selected by default) so that non-server users get it installed.