Patrick O'Callaghan <pocallaghan@xxxxxxxxx> 于2020年12月23日周三 下午9:29写道： > > I have a directory I use to hold a Windows VM disk image > (/home/Windows/...), and would like to snapshot it before playing with > the QEMU settings. However it's already part of the /home subvolume, so > is there a way of splitting it off on its own without having to create > a new subvolume and sending the contents over? AFAIK subvolumes can be > hierarchical so it would seem like a useful thing to be able to convert > a subtree without all the copying, but the man page doesn't seem to > address it. You could create a subvolume, use cp --reflink=always to create a reflink, and delete the old directory, this turns a directory into subvolume easily without actual copying. But I don't suggest you do so, since using snapshot/reflink on VM images will make it Copy-on-Write, VM images should be nocow for performance. But can anyone figure out if creating a reflink then removing old references before any write to the file happens turns on CoW for the file? I am not sure. But writing after snapshot definitely turns on CoW. > > poc > _______________________________________________ > users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx > To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx
