Re: OT: data destruction classics (was: Re: Error converting from 1.4.4.1 to 1.5.0?)

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Feb 15, 2007, 10:24 UTC
Message-ID: <Pine.LNX.4.63.0702151103100.448@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <Pine.LNX.4.64.0702141836510.20368@woody.linux-foundation.org>

Hi,

On Wed, 14 Feb 2007, Linus Torvalds wrote:

Show 18 quoted lines

> On Wed, 14 Feb 2007, Shawn O. Pearce wrote:
> 
> > Simon 'corecode' Schubert <corecode@fs.ei.tum.de> wrote:
> > > Bill Lear wrote:
> > > >I'm still muttering to myself that I could be that dumb...
> > > 
> > > Still better than trying to backup with
> > > 
> > > tar czvf data* destfile.tar.gz
> > > 
> > > automatic tape backup is a real helper then :)
> > 
> > or manual backup to "tape", where the tape device supplied was
> > the only disk...  SunOS 4 did not take too kindly to its kernel,
> > swap space, root fs being overwritten...
> 
> Hey, I can beat that (stop me at any time you've heard this story. No? 
> Ok, then..)

We're having a dick contest? Well, I'm game.

> I auto-dialed my harddisk.

I connected a tape drive.

It was a SCSI tape drive, and I had a SCSI Zip drive, which was so often connected/disconnected in-flight that the plug wore out. So I thought that it should not be a problem to connect the SCSI tape drive to a running system. Right? RIGHT?

BIG MISTAKE.

The SCSI adapter also hosted two RAID systems, one as a SCSI RAID, i.e. managed by the adapter, and one as ATAPI RAID, i.e. managed by its own embedded computer simulating one (actually, two) SCSI hard disks to the SCSI adapter.

We wanted to backup some of the data, and that's why we connected the tape drive.

First, we got write errors on the RAID. Then, one RAID (the SCSI one) stopped working at all. The fans still moved air, but the bus no longer moved _any_ bytes.

Panicked (Douglas Adams, where are you when I need you?), I disconnected the tape drive, and the two RAID boxes (all of them were external, so that was possible). I shut down the computer and let out a long breath of hope.

In the course of several weeks, my days started with praying, connecting one or both RAIDs to several SCSI adapter/computer pairings, hoping that I could read _anything_ from them.

All of the data was lost. Four terabytes. 6-7 months work of three people.

To this date, the SCSI RAID is not working. After one week (through which it did not work _at all_), the ATAPI RAID worked again (strangely enough), but had lost the correct order of its 14 disks.

Even if I could reconstruct the correct order after two more weeks, I could not get any data from the RAID, since I had nowhere nearly large enough amounts of free disk space. And I could not teach the RAID the correct order.

And the tape drive still does not work.

Okay, guys, top _that_.

Ciao, Dscho