Ahhhhh, now it makes sense!! Thanks! On Fri, Mar 29, 2013 at 3:27 PM, Hugo Mills <hugo@xxxxxxxxxxxxx> wrote: > On Fri, Mar 29, 2013 at 03:18:03PM +0100, Harald Glatt wrote: >> Sorry I forgot to post that, >> >> -> btrfs fi show >> Label: none uuid: 2feccf06-5af8-4d8a-ad8d-a090cf4ef69a >> Total devices 2 FS bytes used 16.54GB >> devid 1 size 40.90GB used 14.04GB path /dev/sda7 >> devid 2 size 17.75GB used 14.03GB path /dev/sda6 >> >> The array is more of a for-fun and testing thing than a real world >> example. I've simply combined two differently sized partitions on the >> same disk together. >> >> So how much space is actually used now? >> >> On Fri, Mar 29, 2013 at 3:12 PM, Josef Bacik <jbacik@xxxxxxxxxxxx> wrote: >> > On Fri, Mar 29, 2013 at 07:58:40AM -0600, Harald Glatt wrote: >> >> I've run a balance before taking these meassurements: >> >> >> >> -> df -h reports 59G total space, 18G used, 7G free. >> >> -> btrfs fi df / reports the following: >> >> Data, RAID0: total=16.00GB, used=15.58GB >> >> System, RAID1: total=32.00MB, used=4.00KB >> >> System: total=4.00MB, used=0.00 >> >> Metadata, RAID1: total=6.00GB, used=974.36MB > > OK, so you have 14.04+14.03 = 28.07 GiB allocated for immediate use > on the disk. > > Of that 28.07 GiB, > > - 16.00 GiB is assigned for RAID-0, and 15.58 GiB of that is actually > occupied by useful data. > > - 6.00*2 = 12.00 GiB is assigned for use by RAID-1 metadata, giving > 6.00 GiB of usable metadata. 974.36 MiB of that contains actual > metadata. > > - 68.00 MiB (2*32.00 + 4.00) is the remainder, assigned to the system > chunks (actually the chunk tree), of which 4 KiB is actually useful > data. > > Now, since you have RAID-0 data, the FS requires at least two > devices to stripe across. So the best it can manage is to add a > further 3.75 GiB of data chunks on each device (because /dev/sda6 has > 3.75 GiB not allocated). 3.75 GiB on two deivces for RAID-0 is 2*3.75 > = 7.5 GiB reported free by df. > > HTH, > Hugo. > > -- > === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === > PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk > --- Gentlemen! You can't fight here! This is the War Room! --- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
