RE: ext3 journal on software raid (was Re: PROBLEM: Kernel 2.6.10 crashing repeatedly and hard)

You forgot one!
Peter said: "There might be a small temporal displacement."

This worries me!  RED ALERT!
Beam me up!  Wait, I will take the shuttle craft please.
"You cannot change the laws of physics!" - Scotty

But, really, I do understand what Peter is saying.  It just seemed too funny
to me.  And since I have disk read errors more than temporal displacement, I
need RAID more than a temporal dampening field.  Maybe a temporal phase
converter?

And, a single non-RAID disk can suffer from temporal displacement.

I love Star Trek, so I love temporal displacements!  :)

Guy

-----Original Message-----
From: David Greaves [mailto:david@dgreaves.com] 
Sent: Wednesday, January 05, 2005 12:27 PM
To: Guy
Cc: linux-raid@vger.kernel.org
Subject: Re: ext3 journal on software raid (was Re: PROBLEM: Kernel 2.6.10
crashing repeatedly and hard)

Guy wrote:

RAID does not cause bad data!
 

Guy - how can you speak such heresy!!      ;)
Haven't you seen the special 'make_undetectable_error(float p)' function?

Bad data can get on any disk, even if it is part of a RAID system.
The bad data does not come from the hard disk, CRCs prevent that.

The problem is:  Where does the bad data come from?
Bad memory?  No, everyone use ECC memory, right?
 

I like to blame cosmic rays - I just like the image ;)

Of course voltage fluctuations, e/m interference, thermal variations, 
mechanical interfaces, dust capacitance/resistance, insects shorts... 
anywhere inside the tin box between the media and the corners of the 
motherboard. It's amazing that some machines even boot.

David