[plug] Disk Partitioning & Dial on Demand questions

[Nick Bannon]

On Fri, Mar 10, 2000 at 09:43:22AM +0800, Chris Griffin wrote:
[...]
> The system has two drives in it. The first is a 4GB of which I can have 
> 1Gig for the system, the rest is for user data area. With all of the system 
> and facilities I had to install, it left me with that partition 93% full. 
> For this reason I fitted an old 240MB drive as a secondary and would like 
> to add this into the system. This raises two questions for me.
> First, should I just move /var onto this drive or should I move other areas 
> onto it as well.

As people suggested, some swap could be a good idea.

> Secondly, how do I move it over without having to reinstall the system?
[...]

OK, guessing wildly, your first 4GB hard disc is /dev/hda, second 240MB
hard disc is /dev/hdc. You have something like ;

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>	<pass>
/dev/hda1       /               ext2    defaults,errors=remount-ro	0	1
/dev/hda2       none            swap    sw		0	0
/dev/hda3	/space		ext2	defaults	0	2

Use "cfdisk /dev/hdc" to make a (240-64)MB Linux /dev/hdc1 and a 64MB
Linux swap /dev/hdc2.

Substitute names, devices and partition numbers as appropriate. /space
is that 3GB user data partition you mentioned.

Now, after carefully checking that you're formatting the right disc...

	mkfs.ext2 /dev/hdc1
	mkswap /dev/hdc2

Now - boot to single user mode. You can get away without it if the
machine's not in use, but it means you won't lose any log file entries
that you make in the next few minutes, etc.

	mkdir /mnt/tmp
	mount -t ext2 /dev/hdc1 /mnt/tmp
	(cd /var && tar c .) | (cd /mnt/tmp && cpio -im)
	mv /var /my_old_copy_of_var
	mkdir /var
	chmod 755 /var

That'll copy /var over, with ownership, permissions, etc. You should
also be able to use dump and restore, or something like
"find /var -depth | cpio -pm /mnt/tmp".

Now edit your fstab to look like ;
# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>	<pass>
/dev/hda1       /               ext2    defaults,errors=remount-ro	0	1
/dev/hdc1       /var            ext2    defaults	0	2
/dev/hda2       none            swap    sw,pri=0	0	0
/dev/hdc2       none            swap    sw,pri=0	0	0
/dev/hda3	/space		ext2	defaults	0	2

Lo and behold! Two swap partitions striped together for extra speed.
/ is mounted first and fscked in pass 1, then /var and /space are
fscked in pass 2, in parallel.

Tell us how it all goes.

Nick.

-- 
  Nick Bannon  | "I made this letter longer than usual because
nick at it.net.au | I lack the time to make it shorter." - Pascal