On Sun, Jan 10, 2021 at 4:39 PM Matthew Miller <mat...@fedoraproject.org> wrote: > > On Sun, Jan 10, 2021 at 11:09:31PM +0000, Patrick O'Callaghan wrote: > > > It's not possible to set this attribute once a file has data in it, it's > > > not retroactive. You'll need to duplicate the file, in that same > > > directory. > > > Because the directory has the attribute now, the duplicate will inherit > > > the > > > attribute. > > > > That's somewhat painful as the file is over 900GB and will need to be > > copied to another drive and then back again, but thanks anyway. > > Can you use `cp --reflink=always`?
No, it will fail. A reflink copy creates shared extents. It can't change them between datacow and nodatacow. Whatever they are in the source, datacow or nodatacow, they must be in the copy. If the +C attribute is set on the enclosing directory, and the file being copied is datacow - there's a mismatch. A cp operation requires a conventional copy in this case, to create the nodatacow extents. But with --reflink=always, the conversion is disallowed, so the cp will fail. This applies to both directions, so it's datacow<-->nodatacow, is a conventional copy operation. It also means as long as you aren't switching between them, you automatically get a reflink copy because the default on Fedora 33 is cp --reflink=auto, i.e. it'll try to reflink copy if it can, and if it can't it'll fall back to a conventional copy. -- Chris Murphy _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org 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@lists.fedoraproject.org
