Where is my 2G? - MC

[Mark Newton]

Brian Astill wrote:

> On Friday 13 April 2007 20:47, Mark Newton wrote:
>> Brian, filling a filesystem doesn't harm it.
> 
> Oh Dear, Mark - but it DID!
> I could not see the contents of /mnt/hdb2 when unmounted.  OK?

You said you couldn't unmount it because when you tried it
said, "filesystem busy."

You also said the directory only contained a lost+found directory.
They're found at the root of filesystems;  The presence of the
lost+found directory in /mnt/hdb2 is evidence that you still had a
filesystem mounted on it.

> If the truth doesn't happen to coincide with what you "know" 
> could/should/would happen - well that's sad.

Given that you freely admit that you don't know what was going
on, I find it amusing that you cling to this theory that filling
up filesytems can damage them.  It's as if you've been groping your
way through an all-obscuring fog of doubt, yet you still claim
infallible knowledge about this one little aspect of the story.

> BTW, please don't imply I wasn't reporting truthfully.  

I'm not implying that.  I'm implying that you were/are a bit confused
after something unexpected happened.  I'm sure you're very sincere about
it.  Sincere and wrong.

Just like you were sincere and wrong when you blamed it on a bug in
mc.

There are millions of Linux systems installed all over the world.
At least one of them would suffer from a full filesystem every single
day of the week.  If filling up filesystems damages them so badly that
you need fsck to recover them, why do you think your story is the -first-
we've heard of this?  Why aren't we hearing about this every time someone
fills up their filesystems?  How come I've been on this list since
it was known as "salug at tafe.sa.edu.au" and I've never heard of a story
like this until yours came along?  How come I've filled up lots of
filesystems on lots of Linux systems over the last fifteen years and
I've never seen anything like what you've described?  How come companies
aren't saying, "Geez, this Linux stuff is unreliable, you have to
run a data recovery utility and reboot whenever you run out of space.
Lets all go back to Vista!"?  How come you can try this out -right now-
by filling up one of your filesystems again, then deleting the offending
files, and observing that you get your free space back?

Your account is 100% consistent with the following flow of actions:

   1.  Copying enough data into /mnt/hdb2 to fill it up;

   2.  Mounting /dev/hdb2 on top of it, thereby obscuring it;

   3.  "cd /mnt/hdb2; ls" to confirm that your stuff is there;

   4.  Trying to unmount /mnt/hdb2 and failing beacuse you've just
       cd'ed into it (with a shell, GNOME, mc, or whatever)

   5.  Not realizing that the unmount has failed, and continuing
       on the erroneous assumption that 2 Gbytes of stuff has actually
       been deleted from your root disk without giving up any free
       space.

When you shut the system down, it'd have unmounted /dev/hdb2.
Then you'd have been able to delete the offending bits, and you'd
have got your space back.  There was no need to run fsck.

A less intrusive way of getting the space back would have been to
use lsof to find out which processes had files open on /mnt/hdb2,
killing those processes, unmounting the filesystem (successfully,
this time), and deleting the files.  Much better, 'cos then you
wouldn't have needed to shut down, wouldn't have needed to reboot,
and wouldn't have been confused about the real nature of the
real problem.

   - mark

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I tried an internal modem,                    newton at atdot.dotat.org
      but it hurt when I walked.                          Mark Newton
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