On 9/14/05, andy <dancer@axelrod.plus.com> wrote:
I
> Easily done. Mount your NT partition through samba, and run dd. An
> example would be:
>
> dd if=/dev/cobd0 of=/mnt/disk.image

well at image creation time I will be running linux native
not CL so I can mount the partition directly  but I think
it doesn't want mounting (I just need access to the device
file in /dev I think).

Presumably what I do is

dd if=/dev/hda3 of=/somepathToFileOnSomeDisk

is that correct ?  What about block size ?

Ack.. yes.. of course.. I was still in "colinux mode".. you should be dd'ing /dev/hda3 instead of /dev/cobd0. But yes, that syntax is correct. Usually it will work with no block size set (there is some default that generally works).

>     a) For the linux-in-a-partition that also runs with CL on
>     w2k is there a size limit - does that partition have
>     to be <= 4G to run with CL w2k ? (that would be a shame).
>
>
> No. This 4gig file limit only applies to FAT32, AFAIK. Even NTFS can
> work with images larger than 4gig (I've run 6 gig images before). Also,
> if you're running FAT32 on a colinux system, you can get around this 2
> gig limit by using RAID devices if disk size is upmost importance (and

That was my question.  My daughter's machine has FAT32 so I presume I
can only use up to 2G if I want to use it with CL on there.
I could *build* it on an external disk but that subverts one aim which
is to leave the running system on her machine as well.

I would seriously suggest using RAID0 in this case. You'd have to build a customer kernel, but I'm going to work on a way to properly
document this so that its pretty straight forward. It effectively takes a "list" of 2 gig files and just concatenates them into a large
disk. That way, you can make 10 or even 20 gig drives for Linux to use (as long as you don't mind a lot of disk files laying about).

The point is that since it will run on my box which is ntfs its a shame
if it has to be limited to 2G.  I'd move her to xp cept it aint so
freely avail without license as w2k.

Aye. With the above comment, though, you should be able to break the 2 gig limit (at least on the linux side, not on the FAT32 side).

An off-topic:
I had thought of running her box on ntfs - anyone know, what does
ntfs do functionally (above block level/fs access level) that's
different to FAT32 ?  I mean could I rsync/tar/whatever her system,
format a partition as ntfs and put it on there ?  Since I read
in many places that linux doesn't support ntfs functionality I
always presumed there was functionality related to the OS
implemented in it differently to on fat32 so that you couldn't
just lift a w2k system from one and plonk it on another and have it
run.  Is that correct ?  What is it that isn't implemented
in normal unix filesystem access to ntfs that would make that
not work ?

NTFS offers a lot of advancements that some say slow it down and others say don't affect performance at all. Some of the list are:

1. Larger files (as demonstrated above)
2. File ownership (much like UNIX)
3. File security (like modes in UNIX)
4. Sparse files (effectively compressing blank space, much like MP3 compression)
5. Journalling to assist in file recovery if the disk is corrupted (a lot of people say this is what slows down the FS, but its debateable)

There are other advancements, but these are the big ones I can think of now.

I'm a little confused about your last question regarding UNIX and NTFS, but I think you mean "Why can't you mount an NTFS partition
in UNIX?". As far as I know, the format of NTFS is proprietary, and Microsoft isn't giving out the white papers on the filesystem layout,
so a lot of people are figuring out the format by hand. Apparently, this isn't as easy as it sounds, since it hasn't been successfully done
yet (well, thats a lie.. it has been done, and read support is available, but write support is shaky.. it works for those files that are overwritten
and not changed in size, but not for new files, or files that you want to overwrite and change the size of).

Ian