Re: Bug in btrfs-debug-tree for two or more devices.

[Arne Jansen <sensille@gmx.net>]

On 06/12/2012 08:53 AM, Santosh Hosamani wrote:
> 
> Hi btrfs folks,
>                 I am working on btrfs filesystem on how it manages the free space. And found out btrfs maintain a ctree which manages the physical location of the chunks and stripes of the filesystem.
> Btrfs-debug-tree also gives the information on the chunk tree
> 
> I created btrfs on single device and two device.I have attached the output of both on running btrfs-debug-tree.
> For single device sum of all the length in the chunks will add upto the total used bytes which is expected behavior.
> 
> But for two devices sum of all lengths in the chunks does not add to the total bytes .Am I missing something .
> Also I notice that for the second device the superblock location 0x10000 is not considered as used .
> 
> I would be really grateful if you folks can answer my query.

It's definitely not a bug in debug-tree, but just a problem in
interpreting the result. Could you please paste the output of
btrfs-debug-tree -d? This way it is easier to see what's
bothering you :)

> 
> I hav run these tests on SLES11-sp2-x86
> Kernel 3.0.13.0.27-default
> 
> If you want any further clarification I would be wiiling to help you guys on this.
> 
> Thanks,
> Santosh Hosamani
> 
> 
> 
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