[lug] Feedback Wanted - Proposed Open Source Disk Test SW

[George Sexton]

Steve Sullivan wrote:
> Hi George,
> 
> Judging from the docs, Jonnie looks like a useful package that fills a need.
> A few questions ...
> 
> Why would someone want to set the TestCorruption flag?

It's a built-in self test mechanism. I thought that if the whole point 
was to catch read-errors, I should have some way of assuring myself they 
would actually be caught.

> 
> Do all the files (and all the blocks for that matter) have different
> data?  That is, are they all written from a single RNG with a long
> period?  That way if a bad driver reads the wrong block, Jonnie can
> detect it.

The files for sequential and random IO each have different random blocks 
of data, but within a file the block is the same. To make every block 
random would require essentially a second file that I would have to 
write both the blocks to and then read and compare each other against.

> 
> Is it possible to use Jonnie against an existing file?  Suppose we have
> a huge DBMS that is giving us odd errors.  Could we take the DB down some
> night and use Jonnie to read, change, read-verify, restore, read-verify blocks?

That's an interesting idea that I never thought of. I think that if 
you're running a RAID controller, there should not be any media errors. 
It would seem to me that any kind of errors would be systematic and not 
positional.

It wouldn't be a great deal of effort to adjust the code to look for a 
test file name to use, but again, with a RAID system I would think any 
errors would be systematic.

> 
> Thanks!
> 
> Steve
> 
> On Wed, Jan 02, 2008 at 11:35:03AM -0700, George Sexton wrote:
>> If you follow the list, you've seen my recent comments about the 
>> inadequacy of commonly used disk testing software.
>>
>> To meet my own needs in this area, I've created my own disk test 
>> software tentatively named (wait for it): "jonnie".
>>
>> If there is sufficient interest, I'll GPL the software and throw it up 
>> on Source Forge.
>>
>> Here's a link to the documentation:
>>
>> http://www.mhsoftware.com/jonnie/
>>
>> and a link to the actual application (42KB)
>>
>> http://www.mhsoftware.com/jonnie/jonnie_0.9.zip
>>
>> I would appreciate any feedback you have. In particular, I'm interested 
>> in feedback on the documentation and on the quality of the tests.
>>
>> Things I have in mind for this sw before considering it done are:
>>
>> * Making it possible to localize messages
>> * Perhaps making the Random IO Testing a little more paranoid.
>>
>>
>> -- 
>> George Sexton
>> MH Software, Inc.
>> Voice: +1 303 438 9585
>> URL:   http://www.mhsoftware.com/
>> _______________________________________________
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> 

-- 
George Sexton
MH Software, Inc.
Voice: +1 303 438 9585
URL:   http://www.mhsoftware.com/