Re: Wishlist Item :: One Subvol in Multiple Places

[Robert White <rwhite@pobox.com>]

On 10/15/2014 04:30 AM, Austin S Hemmelgarn wrote:
> On 2014-10-14 18:25, Robert White wrote:
>> I've got no idea if this is possible given the current storage layout,
>> but it would be Really Nice™ if there were a way to have a single
>> subvolume exist in more than one place in hirearchy. I know this can be
>> faked via mount tricks (bind or use of subvol=), but having it be a real
>> thing would be preferable.
>>
>> For example, if I have two or more distributions on a computer or want
>> to switch between 32bit and 64bit environments frequently, but I want to
>> use the same /home (which is its own subvolume anyway) it would be nice
>> if the native layout could be permuted such that /__System_32/home and
>> /__System_64/home were the actual same subvolume.
>>
>> The mechanism, were it possible, would be something like "btrfs
>> subvolume link /existing/path /new/path" (or "bind" instead of "link")
>>
>> I've got no idea if the directory structure would allow for this, but if
>> it would it would simplify several things (for me anyway) if the file
>> system layout represented the runtime layout.
> This probably won't be implemented, for the same reason that most modern
> unix systems disallow hardlinks to directories; namely, it results in
> ambiguity regarding resolution of the .. directory entry.
> The better solution would be to put /home in a separate top-level
> sub-volume, and then mount that in each location.

Oh. Duh. I knew that...

Some days the brain, you know... 8-)

--Rob.