[svlug] Files That Will Not Delete

Steve Litt slitt at troubleshooters.com
Sun Nov 2 09:04:01 PST 2014


On Sun, 02 Nov 2014 08:20:38 -0800
Michael Eager <eager at eagercon.com> wrote:

> On 11/02/14 08:03, Scott DuBois wrote:
> > On 11/02/2014 04:29 AM, Karen Shaeffer wrote:
> >> Hi Scott,
> >> You do not have to physically touch a connector for the connection
> >> to fail. The connection surfaces can corrode over time. This is
> >> caused by a compositional difference of the two contacts, which
> >> creates an electrical difference at the point of contact, that
> >> causes impurities to diffuse out of the contacts towards the
> >> surface. In really cheap contacts, there can also be oxidation at
> >> the surface as well. Re-seating contacts cleans the surface due to
> >> abrasive effect between the two contact surfaces. This problem is
> >> quite common with cheap commodity hardware.
> >>
> >> High quality electrical contacts are made of gold.
> 
> 
> > However, couldn't we eliminate the connector as all is working and
> > fine now since formatting to ext4? Wouldn't a bad connection
> > disrupt _all_ I/O?
> 
> The main characteristic of intermittent failure is that it is
> intermittent. Disk drives jiggle as they are accessed.  A "works
> almost all the time" connection might fail only when the drive moves
> and breaks the connection.
> 
> If you can get to the contacts, take a plain rubber eraser
> and rub it gently on the contacts and blow/brush off any dust.

This reminds me of the following incidents that happened to me:

http://troubleshooters.com/tpromag/200504/200504.htm#_Relapse_The_Persistent_Intermittent

http://troubleshooters.com/tpromag/200504/200504.htm#_The_Keyboard_Assaulted_the_Computer

Just gotta love those intermittents!

SteveT

Steve Litt                *  http://www.troubleshooters.com/
Troubleshooting Training  *  Human Performance





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