Re: Simulating faulty disk

[Yathindra <ydev@cs.utah.edu>]

Hi,

Can anybody with experience in using scsi_debug driver tell me if it can
be used to inject medium errors on various file/disk blocks.

And also, can it delay commands so we can simulate an unresponsive disk.

Thanks,
Yathi
On 10/20/2011 1:30 AM, Yathindra wrote:
> Hi Bryan,
>
> I saw this too but it does not have features to delay the commands. 
> And it works only at the file level.
>
> I thought about scsi_debug driver but it seems to able to inject 
> medium errors on sector 0x1234 only.
> I'm not sure why that limitation exists though.
>
> Thanks,
> Yathi
> On 10/19/2011 10:47 PM, Bryan Mesich wrote:
>> On Wed, Oct 19, 2011 at 09:18:57PM -0600, Yathindra wrote:
>>> Hi,
>>>
>>> I'm trying to simulate a faulty disk behavior on linux. Basically, I
>>> want to inject various disk failure patterns
>>> such as medium errors, unresponsive disk etc.
>>>
>>> What is the best way to go about it. I heard about scsi_debug driver 
>>> but
>>> it can only simulate medium
>>> errors on fixed sector 0x1234. Also, scsi fault injection using
>>> Systemtap seems to be a user space tool
>>> limited to files.
>>>
>>> Any suggestions is greatly appreciated.
>> I saw this go by the linux-scsi list a while back thinking it
>> might be useful sometime down the road:
>>
>> http://lwn.net/Articles/265187/
>>
>> I think the project is hosted on sourceforge.net at the following
>> URL:
>>
>> http://scsifaultinjtst.sourceforge.net/
>>
>> I had also read through part of a paper that was co-authored by
>> the same person (from linux symposium 2008):
>>
>> http://www.linuxsymposium.org/archives/OLS/Reprints-2008/tanaka-reprint.pdf 
>>
>>
>> Doesn't look like there has been much activity since 2009, but it
>> looks like it has the functionality you need.
>>
>> Bryan
>>
>>> Thanks,
>>> Yathi
>