Re: DD-ing from device to device.

[Andreas Dilger <adilger@turbolabs.com>]

On Nov 19, 2001  21:13 +0100, Rogier Wolff wrote:
> Andreas Dilger wrote:
> > dd if=/dev/zero of=tt bs=1k count=1 seek=16M
> 
> 
>  /tmp> dd if=/dev/zero of=tt bs=1k count=1 seek=16M
> dd: tt: Invalid argument
> 1+0 records in
> 1+0 records out

Invalid argument is probably from ftruncate.

>  /tmp> dd if=/dev/zero of=tt bs=1k seek=2047k
> 19913+0 records in
> 19912+0 records out
> ^C
>  /tmp> ls -al tt
> ls: tt: Value too large for defined data type
>  /tmp> su
> Password: 
>  /tmp# rm tt
> rm: cannot remove `tt': Value too large for defined data type
>  /tmp# mv tt xx
> mv: tt: Value too large for defined data type
>  /tmp# rm -f tt
> rm: cannot remove `tt': Value too large for defined data type
>  /tmp# dd if=/dev/zero of=uu bs=1k count=2050 seek=2047k
> 2050+0 records in
> 2050+0 records out
>  /tmp# l uu
> ls: uu: Value too large for defined data type
>  /tmp# 

Looks like your fileutils and/or shell and/or glibc are conspiring against
you.

> > Can you test the "dd" above to ensure it works with your tools and the old
> > kernel?  For your next 2.4.14 kernel build, it may be instructive to put
> > a printk() inside the 3 checks in generic_file_write() before it outputs
> > SIGXFSZ, which tells us limit and RLIM_INIFINITY, pos and count, and pos
> > and s_maxbytes are, respectively.  This will also tell us what limit is
> > being hit (although it is most likely a ulimit issue).
> 
> Grmbl...  I'll see what I can do. 

Start by upgrading your tools to largefile aware ones.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/