Re: mount btrfs takes 30 minutes, btrfs check runs out of memory

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

John Ettedgui wrote on 2015/07/31 21:35 -0700:
> On Thu, Jul 30, 2015 at 10:45 PM, John Ettedgui <john.ettedgui@gmail.com> wrote:
>> On Thu, Jul 30, 2015 at 10:40 PM, Qu Wenruo <quwenruo@cn.fujitsu.com> wrote:
>>>
>>> It seems that you're using Chromium while doing the dump. :)
>>> If no CD drive, I'll recommend to use Archlinux installation iso to make a
>>> bootable USB stick and do the dump.
>>> (just download and dd would do the trick)
>>> As its kernel and tools is much newer than most distribution.
> So I did not have any usb sticks large enough for this task (only 4Gb)
> so I restarted into emergency runlevel with only / mounted and as ro,
> I hope that'll do.
>>>
>>> It's better to provide two trace.
>>> One is the function tracer one, with "btrfs:*" as set_event.
>>> The other is the function_graph one. with "btrfs_mount" as
>>> set_graph_function.
> So I got 2 new traces, and I am hoping that these are what you meant,
> but I am still not sure.
> Here are the commands I used in case...:
>
> trace-cmd record -o
> trace-function_graph.dat -p function_graph -g btrfs_mount mount MountPoint
>
> and
>
> trace-function_graph.dat -p function -l 'btrfs_*' mount MountPoint
> (using -e btrfs only lead to a crash but -l 'btrfs_*' passed, though I
> am sure they have different purposes.. I hope that's the correct one)
>
> The first one was so big, 2Gb, I had to use xz to compress it and host
> it somewhere else, the ML would most likely not take it.
> The other one is quite small but I hosted it in the same place....
> Here are the links:
> https://mega.nz/#!8tgTjKyK!XJnWH05bsv9sJ3nANIxKsdkL20RePPS4cKgWSxit0eQ
> https://mega.nz/#!xopkVA6L!z9xjo3us1Nv6wdOs05jNZdhNbiAP5yeLdneEp0huUzI
>
> I hope that was it this time!
Oh, you were using trace-cmd, that's why the data is so huge.

I was originally hoping you just copy the trace file, which is human 
readable and not so huge.

But that's OK anyway.

I'll try to analyse it to find a clue if possible.

Thanks,
Qu
> Thanks,
> John
>