Re: ext3 issue..

[Davy Durham <pubaddr2@davyandbeth.com>]

I was thinking about delving into this problem a bit.   I don't have any 
unpartitioned free space on my physical drive.  I was going to ask if 
it's possible to create a virtual device in RAM or in a file that I 
could then create an ext3 file system on for testing.. I'm at least 
trying to recreate the situation of the negative diskspace usage.. then 
maybe try to debug ext3 a bit.  At first I thought "oh RAMFS!", then "no 
wait, I couldn't create an EXT3 file system that way".. I need a 
non-physical (block? or character?) device.

Thanks,
  Davy



Davy Durham wrote:

> Greetings,
>   I'm having an issues with ext3.  For about 3 months the /home 
> partition has had low-to-medium use/activity.. adding files, nightly 
> log rotations, some mysql dbs coming and going at a slow pace..  Well, 
> yesterday after I had migrated everything off of it (no files in /home 
> anymore) the df output looked like this:
>
> # uptime
> 10:35:54 up 96 days, 14:22,  1 user,  load average: 0.00, 0.00, 0.00
> # df -h
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/ide/host0/bus0/target0/lun0/part1
>                      2.0G  483M  1.4G  26% /
> /dev/ide/host0/bus0/target0/lun0/part6
>                       33G  -64Z   31G 101% /home
>
> I did notice that if I created a file (cat /dev/zero >/home/foo) of 
> significant size that I could make it look normal again.. So I figure 
> it's an underflow in some count.
>
> Crazy huh?  Well, I unmounted /home and did an fsck -f  on the 
> partition and remounted it.  Then everything looked okay.
>
> ---
>
> Well today on a different server (that I have not cleaned off yet) 
> that has been up and running for 6 months is saying the same thing:
>
> # uptime
> 10:39:16 up 181 days,  2:42,  2 users,  load average: 0.00, 0.00, 0.00
> # df -h
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/ide/host0/bus0/target0/lun0/part1
>                      2.0G  483M  1.4G  26% /
> /dev/ide/host0/bus0/target0/lun0/part6
>                       33G  -64Z   31G 101% /home
>
> Now, this server is still in production.  I could bring it down for a 
> brief time to fsck or reboot it, but I'd be afraid to.  du -h /home 
> shows that really only 268M is used.
>
> If I create a large file (176M) in /home it then don't underflow on 
> the df, but is still incorrect.
>
>
> Is this a known issue with ext3? Or ext2?  Anything I should or should 
> not do about it?
>
> Thanks,
> Davy
>
>
>
>
>
> BTW- df -k looks like
> # df -k
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/ide/host0/bus0/target0/lun0/part1
>                       2054064    493660   1454380  26% /
> /dev/ide/host0/bus0/target0/lun0/part6
>                      33690964 -73786976294838186940  31971456 101% /home
>
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