[rrd-users] ERROR: attempting to write beyond end of file

[Stefan M. Brandl]

On Wed, Dec 29, 2010 at 04:34:42PM -0800, Derek Simkowiak wrote:
>      I am not able to repro, but I did see a different (?) segfault bug.
> 

Hm strange.
But it seems as if I am not alone.
In  http://osdir.com/ml/debian-bugs-dist/2010-07/msg05757.html  a other
user has the same problem.

> derek at derek-laptop:~$ rrdtool create tester.rrd DS:inet:GAUGE:600:0:U 
> RRA:AVERAGE:0.5:1:600
> derek at derek-laptop:~$ ls -la tester.rrd
> -rw-r--r-- 1 derek derek 5344 2010-12-29 16:22 tester.rrd
> derek at derek-laptop:~$ rrdtool resize tester.rrd 0 GROW 100
> derek at derek-laptop:~$ ls -la resize.rrd
> -rw------- 1 derek derek 6144 2010-12-29 16:23 resize.rrd
> derek at derek-laptop:~$
> derek at derek-laptop:~$ rrdtool resize tester.rrd 0 GROW 9900
> derek at derek-laptop:~$ mv resize.rrd tester2.rrd
> derek at derek-laptop:~$ rrdtool resize tester2.rrd 0 GROW 19900
> derek at derek-laptop:~$ mv resize.rrd tester3.rrd
> derek at derek-laptop:~$ rrdtool resize tester3.rrd 0 GROW 29900
> derek at derek-laptop:~$
> 
>      Notice that the error never printed, even after the second and 
> third resize attempts.  Maybe try it on a different filesystem?
> 

On that machine I onle have ext3.

>      I did find a possibly related bug.  If the permissions are such 
> that rrdtool can't write to "resize.rrd", then it segfaults instead of 
> handling the permission error gracefully:
> 
> derek at derek-laptop:~$ chmod 500 resize.rrd
> derek at derek-laptop:~$ rrdtool resize tester3.rrd 0 GROW 29900
> Segmentation fault
> derek at derek-laptop:~$
> 
>      Perhaps Stefan's bug is related.  Stefan, what is the umask on 
> lowrider:/home/ ?  What are the permissions on "resize.rrd" after the 
> first resize attempt?
>

Permissions are ok:
-rw-r--r--    1 noc      noc          6148 Dec 30 08:16 resize.rrd

I also tried it in /tmp
Same result.

> 
> derek at derek-laptop:~$ rrdtool -V | head -2
> RRDtool 1.3.8  Copyright 1997-2009 by Tobias Oetiker <tobi at oetiker.ch>
>                 Compiled Feb 23 2010 20:48:05

Tried it with 1.4.4 and 1.4.5
both compiled from source on
Linux lowrider 2.6.32.24 #9 SMP Mon Oct 4 08:51:42 CEST 2010 i686 unknown unknown GNU/Linux


Stefan