Re: crashblk: a block device crash emulator.

From: Josef Bacik
Date: Fri Jan 15 2016 - 15:10:12 EST

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@xxxxxxxxxxxxxxxxx> 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,