[TriLUG] using parted to change the size of a loop mounted filesystem

[Joseph Mack NA3T]

On Wed, 14 Mar 2012, Robert Dale wrote:

> Note our 96M filesystem.  Now let's grow it!
>
> # umount /mnt
> # dd if=/dev/zero of=foo.part bs=1M count=100 seek=100
> 100+0 records in
> 100+0 records out
> 104857600 bytes (105 MB) copied, 0.152461 s, 688 MB/s

At this stage I have the unchanged original filesystem 
followed by by 100M of 0x00. I had thought that if I 
mouunted it, I would see only the original 100M filesystem. 
However I get "not an ext2 filesystem" and errors about no 
superblook etc. Presumably the only thing wrong is that the 
filesize doesn't match the filesystem size. The superblocks 
etc are still there and in the right place. If I understood 
filesystems better, presumably the problem would be obvious, 
but I don't. What's the problem?

Thanks Joe

-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
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