On Fri, Nov 02, 2012 at 07:05:37PM +0000, Gabriel wrote: > On Fri, 02 Nov 2012 13:02:32 +0100, Goffredo Baroncelli wrote: > > On 2012-11-02 12:18, Martin Steigerwald wrote: > >> Metadata, DUP is displayed as 3,50GB on the device level and as 1,75GB > >> in total. I understand the logic behind this, but this could be a bit > >> confusing. > >> > >> But it makes sense: Showing real allocation on device level makes > >> sense, > >> cause thats what really allocated on disk. Total makes some sense, > >> cause thats what is being used from the tree by BTRFS. > > > > Yes, me too. At the first I was confused when you noticed this > > discrepancy. So I have to admit that it is not so obvious to understand. > > However we didn't find any way to make it more clear... > > > >> It still looks confusing at first… > > We could use "Chunk(s) capacity" instead of total/size ? I would like an > > opinion from a "english people" point of view.. > > This is easy to fix, here's a mockup: > > Metadata,DUP: Size: 1.75GB ×2, Used: 627.84MB ×2 > /dev/dm-0 3.50GB
I've not considered the full semantics of all this yet -- I'll try to do that tomorrow. However, I note that the "×2" here could become non-integer with the RAID-5/6 code (which is due Real Soon Now). In the first RAID-5/6 code drop, it won't even be simple to calculate where there are different-sized devices in the filesystem. Putting an exact figure on that number is potentially going to be awkward. I think we're going to need kernel help for working out what that number should be, in the general case. Again, I'm raising minor points based on future capabilities, but I feel it's worth considering them at this stage, even if the correct answer is "yes, we'll do this now, and deal with any other problems later". Hugo. > Data Metadata Metadata System System > Single Single DUP Single DUP Unallocated > > /dev/dm-16 1.31TB 8.00MB 56.00GB 4.00MB 16.00MB 0.00 > ====== ======== =========== ====== =========== =========== > Total 1.31TB 8.00MB 28.00GB ×2 4.00MB 8.00MB ×2 0.00 > Used 1.31TB 0.00 5.65GB ×2 0.00 152.00KB ×2 > > Also, I don't know if you could use libblkid, but it finds more > descriptive names than dm-NN (thanks to some smart sorting logic). > > -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- My doctor tells me that I have a malformed public-duty gland, --- and a natural deficiency in moral fibre.
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