Re: Possible solution to the "open_ctree" boot bug ...

[George Mitchell <george@chinilu.com>]

On 06/06/2013 01:58 PM, Kai Krakow wrote:
> George Mitchell <george@chinilu.com> schrieb:
>
>> I am seeing a huge improvement in boot performance since doing a system
>> wide file by file defragementation of metadata.  In fact in the four
>> sequential boots since completing this process, I have not seen one
>> open_ctree failure so far.  This leads me to suspect that the open_ctree
>> boot failures that have been plaguing me since install have been related
>> to metadata fragmentation.  So I would advise anyone else experiencing
>> open_ctree boot problems to defragment their metatdata and see if that
>> helps.  It certainly seems to have helped me in that regard.
> I suspect this observation comes from btrfs being able to faster initialize
> itself during kernel detection since you defragmented it. Try to add
> root_delay=2 to your kernel command line and see if it improves on this
> particular problem.
>
> I had this myself and root_delay=1 fixed it for me. Before, in about 90% of
> all boots it came up with the ctree error. After, it never happened again.
>
> Regards,
> Kai
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
Thanks,  I tried that route and it, unfortunately, did not do anything 
for me.  But the defragmentation continues to do the job every time.  I 
am now going to make everything on the OS side "nodatacow" and am 
expecting that will further relieve the problem. The problem NEVER 
occurs in a normal environment, only in the initrd environment.  There 
is something uniquely different about the initrd environment that 
triggers this problem.