Tar oddity...

[DB]

On 12/22/2009 09:51 PM, Roberto Ragusa wrote:
> DB wrote:
>
>    
>> Just tried to copy the file on the F12 laptop... only 324MB of 1.7GB get
>> copied.
>>      
> It looks like you could have some stability issues.
>
> I would try some basic test for your hardware.
> For example:
>
>    while true; do md5sum somefilewithdimensionabout50MB; done
>
> Are the checksum all the same or do they change? If they change,
> causes could be: overclocking, bad power supply, bad RAM, bad CPU
> or software issues (bad kernel, unstable drivers).
>
> Try then with a bigger file, so it will have to read the disk.
> You can try the external disk, so you will test the USB part too.
> Create a file of 500MB with:
>
>    dd if=/dev/urandom of=myfile bs=1048576 count=500
>
> (replace 500 with what you want), then checksum it
>
>    while true; do md5sum myfile; done
>
> use a dimension bigger than the RAM you have on your machine,
> so you defeat the caching that Linux will try to do.
>
> Another test could be
>
>    [create some file called a]
>    cp filea fileb
>    while true; do cmp -l a b;done
>
> The idea is do have the machine do a lot of work for which you
> already know the results. If you get a bad answer (a and b are
> different??) you know the machine is not working well.
>
>    
Ciao Roberto,

Thanks for the testing suggestions!

So.. what I get is:
-no problems when running on the F11 Desktopfor either the md5sum or the 
cmp, run in a while loop for a long time;
-variable numbers of md5sum errors running on the F12 laptop (for 
example, will run 3 times with same checksum then 1 error); variable cmp 
errors(again, one or two clear runs then a pile of miscompares, then 
again several ok runs);
-Ran memtest overnight without error;
-tried the F12-KDE Livecd, sometimes ark opens the files, sometimes not 
(also tried various USB ports both direct & via a powered 7port hub with 
same results);
-tried F11-KDE Livecd, ark opens all files without error.....

On the F11 Desktop, the ark "help-about" gives ARK Version 2.13 using 
KDE 4.3.4,
on the F12 Laptop gives ARK version 2.13 using KDE 4.3.4,
F11 Livecd gives ARK versio 2.12, using KDE 4.2.2,
with yumex, I find that tar on the F12 is 1:22-10.fc12 arch 1686, on F11 
is 2:1.22-4.fc11 arch i586,
as I couldn't find any ark info through yumex, I had a look at 
/usr/bin/ark on both machines: on the F12 machine it is 54.7 KiB, on F11 
is 143.2 Kib.

If /usr/bin/ark is fubared, any idea how I can best put it right?

Again, many thanks for your help

Dave