[ILUG] Partitioning trouble

[Paul Jakma]

On Wed, 31 May 2006, Joe Fitzsimons wrote:

> I've just resized my windows partition with YAST in Suse 9.3, and I want to
> extend my /home and /usr partitions into that space. Unfortunately I seem to
> have been left with space in the middle that I can't access. Any ideas what
> is going on?

> (parted) print
> Disk geometry for /dev/sda: 0.000-76319.085 megabytes
> Disk label type: msdos
> Minor    Start       End     Type      Filesystem  Flags
> 1          0.031  33805.800  primary   ntfs        type=07
> 2      60000.579  63318.691  primary   ext3        boot, type=83
> 3      63318.691  70315.751  primary   ext3        type=83
> 4      70315.752  76316.594  extended              type=05
> 5      70315.783  75312.531  logical   ext3        type=83
> 6      75312.562  76308.750  logical   linux-swap  type=82
>
>
> When I try to add a new partition I am only allowed to start at the very last
> cylinder.

Because:

1. You can't add any more primary partitions (you have 4, the max)

2. You /can/ add another 'logical' partition, however logical
    partitions may only refer to space within the extended-type
    primary partition.

Given your free space lies outside the extended partition, you have 
absolutely no way to add a partition that references it.

You /could/ however, I think, use device-mapper. Something like:

 	$ dmsetup MyOtherwiseUnuseableDiskSpace << EOF
 	0 X linear /dev/sda Y
 	EOF

Replacing:

- X with the number of blocks of free space

   - it'll somewhere around 66027 or less, but you need to examine the
     existing partition table with some tool that makes it clearer
     *exactly* how many blocks each partition is taking (and exactly
     which block it starts on)

- Y with the start block in /dev/sda of the free space

   - somewhere in region of 51161 or less.

If you get it wrong, you may lose data on your existing partitions. 
(In particular, make /sure/ you don't make X too high or Y too low).

If you don't have device-mapper, you can do a similar trick with 
loopback devices via losetup and the offset argument.

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
Breeding rabbits is a hare raising experience.