Should my /dev/sda2 devices be mounted to a different internal HDD?

You do not mount sda2, it is an extended partition containing sda5 which is a logical partition.

Can you please provide the output of:

df -h; mount

and I can clarify for you.

Tks actionparsnip. Here is the requested output:

Filesystem Size Used Avail Use% Mounted on
/dev/sda1 440G 3.2G 415G 1% /
tmpfs 7.8G 0 7.8G 0% /lib/init/rw
varrun 7.8G 104K 7.8G 1% /var/run
varlock 7.8G 0 7.8G 0% /var/lock
udev 7.8G 156K 7.8G 1% /dev
tmpfs 7.8G 424K 7.8G 1% /dev/shm
lrm 7.8G 2.5M 7.8G 1% /lib/modules/2.6.28-14-generic/volatile
/dev/sdb1 459G 199M 435G 1% /mnt/sdb
/dev/sdc1 459G 199M 435G 1% /mnt/sdc
/dev/sda1 on / type ext3 (rw,relatime,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
varrun on /var/run type tmpfs (rw,nosuid,mode=0755)
varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
lrm on /lib/modules/2.6.28-14-generic/volatile type tmpfs (rw,mode=755)
/dev/sdb1 on /mnt/sdb type ext3 (rw,relatime,errors=remount-ro)
/dev/sdc1 on /mnt/sdc type ext3 (rw,relatime,errors=remount-ro)
securityfs on /sys/kernel/security type securityfs (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/scott/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=scott)

ok can you please provide:

sudo fdisk -l

thanks

Here you go:

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x0ecab17e

   Device Boot Start End Blocks Id System
/dev/sda1 * 1 58336 468583888+ 83 Linux
/dev/sda2 58337 60801 19800112+ 5 Extended
/dev/sda5 58337 60801 19800081 82 Linux swap / Solaris

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xc1839228

   Device Boot Start End Blocks Id System
/dev/sdb1 1 60801 488384001 83 Linux

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xc183923f

   Device Boot Start End Blocks Id System
/dev/sdc1 1 60801 488384001 83 Linux

Disk /dev/sdd: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xccc5c4d9

   Device Boot Start End Blocks Id System
/dev/sdd1 1 121601 976760001 7 HPFS/NTFS

Ok firstly thanks tonne for the info. This has proved most helpful. I can now discuss.

The bit of interest is:

   Device Boot Start End Blocks Id System
/dev/sda1 * 1 58336 468583888+ 83 Linux
/dev/sda2 58337 60801 19800112+ 5 Extended
/dev/sda5 58337 60801 19800081 82 Linux swap / Solaris

Which contains your sda2 you mention in your initial question. If you notice the counters for start and end, both sda2 and sda5 have an identical count starting at 58337 and ending at 60801. this shows that sda2 in an extended partition, sda5 is a logical partition witin that. The start and end blocks do not always have to match and you could have easily had something like this

   Device Boot Start End Blocks Id System
/dev/sda1 * 1 58336 468583888+ 83 Linux
/dev/sda2 58337 60801 19800112+ 5 Extended
/dev/sda5 58337 59569 19800041 82 Linux swap / Solaris
/dev/sda6 59570 60801 19800041 83 Linux

As you can see I simply cut the logical partition /dev/sda5 which resides on the extended partition /dev/sda2 into 2 parts to make /dev/sda6 if you read the block counts you can see exactly what I did (its not real partitioning. I just did some maths and typed a new line)

You cannot mount /dev/sda2 but you can use it as a block device for example if you wanted to use the dd comand to copy all the logical partitions to a new drive, or if you want the virus scan all logicl drives.

Hope this makes sense. If you read it a few times you'll get it.

Tks for the explanation, however, it unfortunately doesn't explain why Storage Device Manager displays sda2 as being mounted to sdc?

sda2 mount point = /mnt/sdc (name=sdc)

I have only mounted sdc1 to that mount point.

Also, why does SDM display sda2 on my desktop, but not on my laptop?

OK, Ubuntu is a mysterious OS, as sda2 is no longer being displayed by SDM, so my desktop is now behaving like my laptop, which I believe is the correct behaviour.

I havent done anything to correct this, so have no clue why it is OK now.