On 03/19/2013 07:52 PM, Martin wrote:
> On 03/18/2013 11:19 PM, Peter Chant wrote:
>> On 03/15/2013 08:07 PM, Martin wrote:
>>> On 03/15/2013 01:37 AM, Peter Chant wrote:
>>>
>>>> Understanding that lilo cannot deal with btrfs as / without putting the
>>>> boot directory on a separate non-btrfs file system I created
>>>> partition 1.
>>>
>>> That part I understand because apparently btrfs has not implemented the
>>> ioctl FIBMAP which is required to map files to block numbers. It's not
>>> Lilo's fault.
>>>
>>
>> Hmm, catch 22. Seems like grub2, syslinux/extlinux can boot btrfs, and
>> since lilo users seem to be a minority and there is other work going on
>> in btrfs I suspect that situation won't change for a while.
>
> maybe there even is a fundamental road block, for instance if the
> filesystem reserves the right to move the files around.
>
Yes. Seems fair. From what I understand grub2 uses a sizeable chunk of
code to read btrfs - I think, but am not totally sure that lilo just
points at the correct section of disk - what I believe you are alluding to.
>> I was having limited
>> success in that I could manage to get a initrd image loaded under
>> certain circumstances.
>
> surely the initrd image is on the non-btrfs-filesystem together with the
> kernel? there should be no issue loading it. better still, all required
> filesystem drivers should be in the kernel image (ie. not compiled as
> modules).
>
I was not sure that I would need it as I compiled btrfs into the kernel
I am using. However, I tried both with and without. I could on
occasion get the initrd image to load but it never seemed to mount the
correct part of btrfs. This was despite hacks to do so and subvol
parameters being passed to the kernel. I can't give a reliable list of
what worked and what did not as I was not attempting a formal test, just
trying to get _something reasonable_ working.
I admit to not having a large degree of success in the past with boot
loading in general. However, it seems all a little more complex than
ideal and is not at all forgiving if it does not work.
>>
>>> Seems to me that btrfs is not ready yet.
>>>
>>
>> It seems to be fairly mature from reading the btrfs site.
>>
>
> they would say that, wouldn't they.
>
ext4 is still being tweaked as well.
Pete