Re: root subvol id is 0 or 5?

[Duncan <1i5t5.duncan@cox.net>]

Hugo Mills posted on Sun, 30 Nov 2014 13:53:28 +0000 as excerpted:

> On Sun, Nov 30, 2014 at 07:08:51PM +0530, Shriramana Sharma wrote:
>> On Sun, Nov 30, 2014 at 5:29 PM, Hugo Mills <hugo@carfax.org.uk> wrote:
>> >
>> >    In the data structures on disk, it's 5. The kernel aliases 0 to
>> > mean subvolid 5.
>> 
>> So why 5 and not just 0 which seems a logical choice? On top of this,
>> one needs to alias 0 to 5!
> 
>    All of the trees used in the FS metadata have an ID number. The
> "well-known" trees have small, fixed IDs:

Thanks, Hugo.

You might wish to find a place in the wiki (probably in the FAQ) for 
that, since your explanation was both the clearest I can imagine and 
cleared up some lingering "but why?" questions along that line for me, as 
well.

And if an answer to that basic a btrfs question is still clearing stuff 
up for me, I expect it could be useful to well over 90% of potential 
btrfs wiki FAQ readers...

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman