800 GByte free, but "no space left"

["Helmut Hullen" <Hullen@t-online.de>]

Hallo,

I've new problems.

I use 2 disks (1.5 Tbyte and 2.0 TByte) under 1 LABEL (for my video  
collection, nearly alle files have more than 1 GByte):

Label: MM2  uuid: ad7c0668-316c-4a79-ba00-3b505b9d99b4
	Total devices 2 FS bytes used 2.38TB
	devid    2 size 1.35TB used 1.35TB path /dev/sdc3
	devid    1 size 1.81TB used 1.35TB path /dev/sdf2

("btrfs-show" uses TiByte, it's 10% less than TByte)

Btrfs Btrfs v0.19

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sdc3            3400799848 2559596740 841203108  76% /srv/MM

--------------------------------

When I add some more videos, writing gets slower and slower, and then  
the system refuses with "no space left ..."

Label: MM2  uuid: ad7c0668-316c-4a79-ba00-3b505b9d99b4
	Total devices 2 FS bytes used 2.40TB
	devid    2 size 1.35TB used 1.35TB path /dev/sdc3
	devid    1 size 1.81TB used 1.35TB path /dev/sdf2

Btrfs Btrfs v0.19

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sdc3            3400799848 2585340332 815459516  77% /srv/MM

---------------------------------

When I try to rename files I get "no space left ...". When I delete some  
files and then try again to rename the system doesn't really rename but  
first copies to the new name and then deletes the old file. Same  
behaviour when I try to move a file from one directory to another.

----------------------------------

Where is the bottleneck?

Viele Gruesse!
Helmut