Sparse files and block devices

Sparse files and block devices

[Randy Barlow]

I started playing with btrfs last night, and I must say that I am very
excited! I do have one question so far. Since I was learning, I created
a sparse file, and then used mkfs to get a btrfs filesystem. I
entertained myself with that for a while, and then decided that I wanted
to try out the multi device support. I found that the device add command
requires the device to be a block device, and wouldn't accept another
sparse file that I had created. Is there a workaround, or is that just
the way it is?

I ended up just making a logical volume to get the second block device.

Thanks for making such a cool fs!

Re: Sparse files and block devices

[Tsutomu Itoh]

(2011/08/08 14:55), Randy Barlow wrote:
> I started playing with btrfs last night, and I must say that I am very
> excited! I do have one question so far. Since I was learning, I created
> a sparse file, and then used mkfs to get a btrfs filesystem. I
> entertained myself with that for a while, and then decided that I wanted
> to try out the multi device support. I found that the device add command
> requires the device to be a block device, and wouldn't accept another
> sparse file that I had created. Is there a workaround, or is that just
> the way it is?

I think that you can use 'losetup' command for this end.

  -Tsutomu

>
> I ended up just making a logical volume to get the second block device.
>
> Thanks for making such a cool fs!