[lug] Hard drive testing tools

[George Sexton]

I've had two problems with Bad Blocks

1) It's done destructively, typically using a bootable distribution like
knoppix. This isn't the configuration you'll be running under so you can't
say anything about how the drivers of the actual distribution are going to
interact with the hardware configuration.

2) It doesn't put the system under load. I've observed systems that work
correctly under minimal system load (e.g. sequential read/write) do not work
correctly under heavy IO load.

Badblocks works OK for evaluating the actual surface of the drive, but for
evaluation of the system as a whole it's inadequate. 

Typically, people use Bonnie/Bonnie++ for this. The problems with those
applications is that they don't actually verify data writes. So, you can use
them all day long but if there's a driver bug it's probably not going to
detect it. This happened to me.

I actually wrote my own Java based application for doing disk testing. It
writes random data to the drives, using a PRNG, and every block has a
different set of data so it can detect overwrites. It does sequential and
random IO.

If you want the Java app, let me know and I'll post a link.

George Sexton
MH Software, Inc.
303 438-9585
www.mhsoftware.com

> -----Original Message-----
> From: lug-bounces at lug.boulder.co.us [mailto:lug-
> bounces at lug.boulder.co.us] On Behalf Of Chris Riddoch
> Sent: Saturday, June 19, 2010 12:55 PM
> To: lug at lug.boulder.co.us
> Subject: [lug] Hard drive testing tools
> 
> I spent some time with the folks at bococo last weekend, and was asked
> about how to test the various hard drives they've been donated.  It's
> quite a variety they have: SCSI, PATA, SATA drives of all different
> sizes.  Some are practically new, others are well worn-in.
> 
> My best guess, based on old information in my head, was to run
> badblocks on the drives, but I also know that there's something wrong
> with just using badblocks, though I don't recall what.
> 
> To those of you working with lots of hard drives, what do you use to
> evaluate the quality of a disk?
> 
> --
> Chris Riddoch
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