Hi, I'm using
# btrfs version btrfs-progs v4.16 In btrfs-subvolume(8), I find the description of the `snapshot` command unclear: snapshot [-r] <source> <dest>|[<dest>/]<name> I find the preference of `|` is unclear. From the text passage If only <dest> is given, the subvolume will be named the basename of <source>. I infer, that `<source>` must be there even “if only <dest> is given”. Also, it's unclear how the cases snapshot [-r] <source> <dest> snapshot [-r] <source> [<dest>/]<name> are told apart. I assume it's based on whether `<dest>` is an existing directory. I came to this from the rather unfortunate error message ERROR: invalid snapshot name '/' when trying # btrfs subvolume snapshot / /foo where `/foo` already existed. It took me some time to arrive at the conclusion that `btrfs` took this as the `<source> <dest>` case, and tried to make a subdir `/` under `/foo`, which is, of course, illegal. May I suggest the following changes: * in the manual, change to: snapshot [-r] <source> <dest> Create a snapshot of the subvolume <source>. If <dest> is an existing directory, the snapshot will be named <dest>/<basename of source>. Note that this is illegal if <source> is `/`. If <dest> does not exist, it will be created, and this will be the snapshot. * in `btrfs subvolume`: Change the error message from ERROR: invalid snapshot name '/' to ERROR: '<dest>' exists, but cannot create snapshot named '/' under it. Specify explicit snapshot name. IMHO it would be better to replace an existing <dest> with the snapshot, instead of creating one under it. It would solve above problem, and also be more similar to how `mount` handles a mountpoint. Thank you, Stefan -- http://stefan-klinger.de o/X Send plain text messages only, not exceeding 32kB. /\/ \ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html