[Lvlug] What happened?

[Mark]

On Saturday 15 April 2006 02:55 am, Darryl Gibson wrote:
> Mark wrote:
> > As fast as df generates it's report it looks like it is just getting its
> > information from the hard drive tables. Are we talking about the same
> > thing? df = disk free, right?
>
> Roger that, I'm assuming that fsck is marking the bad sectors on the disk,
> and df is reporting the good ones?

Actually, the only time a check and mark of bad sectors is done is during a 
fsck.  df simply reports what it 'thinks' the free space is.  If you had the 
right tools you could actually scan your entire hard drive and get different 
numbers than what df reports.  If a sector was previously used and then went 
bad it will still be reported as used space on the drive by df.

> The box is running 24/7/365, so fsck should be running daily.

Not usually, unless your system was configured differently from most default 
installs.  fsck is normally run after a certain number of reboots regardless 
of whether the drive is marked as clean.  If there is an error during any one 
shutdown then the drive will be marked as dirty and a fsck will be forced.  
Finally, in order for any changes/repairs to be made to the drive it has to 
be mounted as read-only.  Yes, that's not a misspelling, it says read-only.  
That gives fsck exclusive access to make the necessary changes to the drive 
without interference from any running processes.

> >>The system was used when I got it, and I've had it four years, so I've
> >> been waiting and preparing for a meltdown.
> >
> > That's a long time to wait for something to go wrong. It must have been
> > running Windows before. :-)
>
> Well, like they say, it is not if, but when. I think I'm backed up, time
> will tell.
>
> Yes, it is a former Windoze box, I bought it at an auction, the drive was
> wiped clean, and reloaded with some kind of minimal Windoze 98 splash
> screen. I dumped that, installed FC1 on it, and it has been my production
> box ever since.

Hmm, go ahead and try a fsck then.  You should be able to do it from 'init 1' 
and then just remount the drive read-only.  I'm using /dev/hda1 as an example 
only.

mount -r -o remount /dev/hda1

should do the trick but look over the man page for mount before you do this.  
Once remounted then run your fsck and use the command line switch to tell it 
to do repairs.  When done remount again

mount -w -o remount /dev/hda1

This will at least eliminate any filesystem related problems as a possible 
cause.

-Mark