Alexander Skwar
2013-May-02 18:33 UTC
Listing EVERYTHING BUT read only snapshots; and what are snapshots if compared with ZFS?
Hello once more... I''m on Ubuntu 13.04 with Ubuntu kernel 3.8.0-19-lowlatency and Btrfs v0.20-rc1. First a clarification question - if I compare btrfs with zfs (which I know better...), how do snapshots compare? A read only snapshot is what ZFS calls snapshots, and a read/write snapshot would be a clone. Is that about right? Now to the real question - how can I *easily* list everything but the read only snapshots? Is there command which does that? With "btrfs subv list -r /home", I can list all read only snapshots under /home. It lists just the read only snapshots. But with "btrfs subv list /home", I see all subvolumes; not only the read/write snaphots. Here''s what I get: root@ask-home:~# btrfs subv list /home ID 257 gen 28776 top level 256 path a root@ask-home:~# btrfs subv list -r /home root@ask-home:~# btrfs subv snaps -r /home /home/foo Create a readonly snapshot of ''/home'' in ''/home/foo'' root@ask-home:~# btrfs subv list /home ID 257 gen 28778 top level 256 path a ID 347 gen 28778 top level 256 path foo root@ask-home:~# btrfs subv list -r /home ID 347 gen 28778 top level 256 path foo Now I''d like to have a command which only shows me the "real" subvolumes. How would I do that? For a script, I came up with this: ( btrfs subv list -r "$mp" ; btrfs subv list "$mp" ) | sort | uniq -u Eg: ( btrfs subv list -r /home ; btrfs subv list /home ) | sort | uniq -u ID 257 gen 28788 top level 256 path a Works, but is "somewhat" complicated (logic behind that - list only read only subvolumes + list all subvolumes and then show only those, which appear just once)... Is there an easier, more straight forward way? Thanks, Alexander -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html