[lug] Max file size

[John Karns]

On Tue, 18 Dec 2001, Sean Reifschneider said:

> On Tue, Dec 18, 2001 at 01:53:02PM -0500, John Karns wrote:
> >I would like to use dd to create a compressed image file of a vfat
> >partition which exceeds 2GB in size, and I bump into the limit which
>
> Well, first of all you can use compression to bring the size down:
>
>    dd if=/dev/hdaN | bzip2 >hdaN.dd.bz2

I had tried compression via gzip but the size was still greater than 2GB.
Seems a bit strange too, since df shows

Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/hda1              6702032   2494860   4207172  38% /dosc

which I thought would very surely compress to less than 2GB.  Stranger
yet, I used a method like you suggest (piped thru gzip) to write a
compressed image to a 4GB Travan TR-4 cartridge, and it overflowed the
tape as well.  Go figure.


> You can also use "split" to have it write to multiple 2000MB files:
>
>    dd if=/dev/hdaN | bzip2 | split --bytes 2000m - hdaN.dd.bz2.

Looks like the solution to my dilemma!  I tried recompiling dd with the
compiler switches that Dan suggested and verified via strace, but
evidently nfs (or reiser) is not allowing a file greater than 2GB.  I'm
using the kernel based nfs, but haven't checked to see what version of nfs
is being used.  I also haven't yet been able to find any reference to the
max file size supported by reiserfs.

Thanx

----------------------------------------------------------------
John Karns                                        jkarns at csd.net