[HLUG] backup old disk

[John Hedges]

On Thu, Jul 12, 2007 at 10:31:45AM +0100, Graham Cole wrote:
> Thanks John, it's about time I understood the partitions but "extended"
> and "Linux LVM" are jargon I don't understand. Both seem to be big so
> neither is a swap partition I guess.
> 
> ~$ sudo fdisk -l /dev/hdc
> 
> Disk /dev/hdc: 20.4 GB, 20490559488 bytes
> 255 heads, 63 sectors/track, 2491 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> 
>    Device Boot      Start         End      Blocks   Id  System
> /dev/hdc1   *           1          31      248976   83  Linux
> /dev/hdc2              32        2491    19759950    5  Extended
> /dev/hdc5              32        2491    19759918+  8e  Linux LVM
> 
> This is what I got:
> 
> ~$ sudo mount -t ext3 /dev/hdc2 /mnt/disk2
> mount: wrong fs type, bad option, bad superblock on /dev/hdc2,
>        missing codepage or other error
>        (aren't you trying to mount an extended partition,
>        instead of some logical partition inside?)
>        In some cases useful info is found in syslog - try
>        dmesg | tail  or so
> 
> :~$ sudo mount -t ext3 /dev/hdc5 /mnt/disk2
> mount: /dev/hdc5 already mounted or /mnt/disk2 busy
> 
> Not busy!? I did umount and checked that /mnt/disk2 was empty. Can it be
> busy while empty? Maybe it's something else and the error message is
> garbled info

Your data is in /dev/hdc5. LVM (logical volume manager) allows you to
combine partitions from multiple drives to make larger logical
partitions. http://en.wikipedia.org/wiki/Lvm

However I don't use it. A google for 'mount lvm partition' gives a few
pointers eg. http://www.techbytes.ca/techbyte118.html

You'll need some lvm tools installed (lvm2).

Cheers

John