Renaming disk partitions

uncle-c · 10-23-2007, 02:59 PM

Hi,
I run the "fdisk -l" command as root on my Ubuntu 7.04 server box the results I get make interesting reading.
There is no /dev/hda1 and Ubuntu is installed on /dev/hda2. There is also an extended partition ( with a logical partition contained within that). When I do a "find" at the grub prompt I get a message that grub is found in (hd0,1). What would be the best way of renaming /dev/hda2 to /dev/hda1. Would the renaming effect my extended / logical partition ?

Thanks
Uncle.

The_JinJ · 10-23-2007, 03:04 PM

Can you paste fdisk -l results here?

uncle-c · 10-23-2007, 03:20 PM

Code:

Disk /dev/hda: 20.8 GB, 20847697920 bytes
255 heads, 63 sectors/track, 2534 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda2               1        2488    19984828+  83  Linux
/dev/hda3            2489        2534      369495    5  Extended
/dev/hda5            2489        2534      369463+  82  Linux swap / Solaris

Obviously I want /dev/hda2 --> /dev/hda1 , hda3 renamed hda2, and hda5 renamed as hda4 !

pixellany · 10-23-2007, 03:54 PM

I'm wondering how you got in this situation---the disk is fully partitioned. But, no matter...

First, it is not really necessary to change this--you can simply change the grub config file to point where you want.

If I am not mistaken, the label is tied only to which entry in the partition table is used. 1-4 are used for primary or extended, and the first logical is always 5. This means that #1 is empty. The only way I know to correct this would be to use dd to move the data. I've never done this, so I can't promise it would work.

Note that your swap space is a bit small--People say things like 2X RAM size, but I always just use 1GB. For this reason alone, I would simply re-partition the drive. you could also re-size #2 and then make a new #1.

If you want to confirm the partition table directly, do this:

dd if=/dev/hda skip=446 bs=1 count=64|hexdump -C
The first and fourth rows should be all zeros, 2 and 3 will have similar entries.

My "booting" link below has more info, including links to the structure of a partition table

uncle-c · 10-24-2007, 03:46 AM

Thanks Pixellany.
The Ubuntu box seems to be working fine, so I may go with the philosophy that "if it ain't broke don't fix it." It was just that having /dev/hda2 and no /dev/hda1 does not look aesthetically correct.

Regards,
Uncle

pixellany · 10-24-2007, 07:42 AM

Quote:

Originally Posted by uncle-c

Thanks Pixellany.
The Ubuntu box seems to be working fine, so I may go with the philosophy that "if it ain't broke don't fix it." It was just that having /dev/hda2 and no /dev/hda1 does not look aesthetically correct.

Regards,
Uncle

That's a good philosophy--I wish I were smart enough to practice it...