Odd BTRFS COW behaviour

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi all,

I've encountered something that seems a little weird and wondering if anyone has any ideas...

My home server has an ext4 root with a btrfs pool mounted at /data (with a number of subvolumes in there).

Within /data I am able to do cp --reflink=always <source> <dest> between subvolumes and COW works as expected.

On my laptop (built with default BTRFS option in F19 and updated to F20) if I try and do a cp --reflink=always <source-in-root> <dest-in-home> (or vice versa direction) it complains that:

cp: failed to clone ‘/tmptest/filename.tar.gz’ from ‘filename.tar.gz’: Invalid cross-device link

There is one key difference I can think of ... although there are separate subvolumes in /data (home, music, downloads, etc) only /data is directly mounted and I'm not explictly mounting the subvolid=music on /data/music or anything like that ...

With the laptop (from the default BTRFS install choice) / and /home are explicitly mounted separately even though they are in the same BTRFS pool.

So far as I understand it when in the same pool cross-subvolume COW should be valid (as shown in /data on the server) - even if technically under separate mounts.

Can anyone else verify the behaviour and is anyone sure of what the correct behaviour should be - if there is a bug is it to file with cp or with btrfs-progs/kernel for example ....

Cheers,

James

-- 
users mailing list
users@xxxxxxxxxxxxxxxxxxxxxxx
To unsubscribe or change subscription options:
https://admin.fedoraproject.org/mailman/listinfo/users
Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
Have a question? Ask away: http://ask.fedoraproject.org
[Index of Archives]     [Older Fedora Users]     [Fedora Announce]     [Fedora Package Announce]     [EPEL Announce]     [EPEL Devel]     [Fedora Magazine]     [Fedora Summer Coding]     [Fedora Laptop]     [Fedora Cloud]     [Fedora Advisory Board]     [Fedora Education]     [Fedora Security]     [Fedora Scitech]     [Fedora Robotics]     [Fedora Infrastructure]     [Fedora Websites]     [Anaconda Devel]     [Fedora Devel Java]     [Fedora Desktop]     [Fedora Fonts]     [Fedora Marketing]     [Fedora Management Tools]     [Fedora Mentors]     [Fedora Package Review]     [Fedora R Devel]     [Fedora PHP Devel]     [Kickstart]     [Fedora Music]     [Fedora Packaging]     [Fedora SELinux]     [Fedora Legal]     [Fedora Kernel]     [Fedora OCaml]     [Coolkey]     [Virtualization Tools]     [ET Management Tools]     [Yum Users]     [Yosemite News]     [Gnome Users]     [KDE Users]     [Fedora Art]     [Fedora Docs]     [Fedora Sparc]     [Libvirt Users]     [Fedora ARM]

  Powered by Linux