Re: crashblk: a block device crash emulator.

[Josef Bacik <jbacik@fb.com>]

On 01/15/2016 01:45 AM, Takashi HOSHINO wrote:
> Hi Andreas,
>
> On 2016/01/15 4:44, Andreas Dilger wrote:
>> On Jan 13, 2016, at 6:50 PM, Takashi HOSHINO
>> <hoshino@labs.cybozu.co.jp> wrote:
>>>
>>> Hi all,
>>>
>>> I'm developing 'crashblk'.
>>> It is a memory block device driver to emulate crash, IO error,
>>> and various response time.
>>
>> Why not use/improve dm-flakey for this, rather than making yet another
>> device that does something similar?
>
> I did not know dm-flakey until your reply. Thank you.
>
> I read its documents and code a bit.
> The big purpose of two projects are the same, which is to test software
> on block devices with errors, but their functions are almost different.
>
> It may be nice idea to implement alternative implementation of crashblk
> on device-mapper version by someone.
> Currently I'm not familiar with device-mapper development, and I do not
> have any motivation with it.
>

There's also dm-log-writes which will log writes to an external journal 
to allow you to replay writes and verify the fs is consistent at all 
steps of operation.  Thanks,

Josef