how not to initialize HD

Gregory Hosler ghosler at
Sun Aug 1 04:08:49 UTC 2010

Hash: SHA1

On 08/01/2010 01:47 AM, Paul Cartwright wrote:
> On Sat July 31 2010, you wrote:
>> The fdisk -l must be done as root.
>>> I can't copy & paste because I am not on that laptop right now..
>> The above output (which you haven't provided, yet) will tell whether you
>> have spare space for an installation, or not.
>> Once that is provided, I, or others, might be able to shed light on your
>> problem.
>> All the best,
> oops, as I found out from another email, I wasn't doing that as ROOT...
> # fdisk -l
> Disk /dev/sda: 100.0 GB, 100030242816 bytes
> 255 heads, 63 sectors/track, 12161 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0xa8a8a8a8
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sda1   *           1        4462    35840983+   7  HPFS/NTFS
> /dev/sda2            4463        4717     2048287+   e  W95 FAT16 (LBA)
> /dev/sda3            4718       12162    59793409    5  Extended
> Partition 3 does not end on cylinder boundary.
> /dev/sda5            4718        5961     9989120   83  Linux
> /dev/sda6            5962        8094    17133291   83  Linux
> /dev/sda7           11919       12162     1951744   82  Linux swap / Solaris
> /dev/sda8            8095       11918    30716248+   c  W95 FAT32 (LBA)

The above clearly describes your problem.

You have no free space to do another install.

you have 12161 cylinders.

	From the 2nd line of the output, which details your disk geometry:
	> 255 heads, 63 sectors/track, 12161 cylinders

Your primary partitions (1 thru 4) map fully, all 12161 cylinders.

	>    Device Boot      Start         End      Blocks   Id  System
	> /dev/sda1   *           1   -->  4462    35840983+   7  HPFS/NTFS
	> /dev/sda2            4463   -->  4717     2048287+   e  W95 FAT16(LBA)
	> /dev/sda3            4718   --> 12162    59793409    5  Extended

Follow the "start" and "end" cylinders. Every cyl between 1 and 12161 (the last
physical cyl) is mapped.

This, in and of itself, is not a problem, as long as one is an extended
partition, which it is.

Now look at the extended partition. The purpose of the extended partition is to
allow partitioning to go beyond the 4 primary. Any of the 4 primary can be
designated as an extended. Many times it is partition 4, but it need not be, and
there is nothing wrong with it not being. In your case it is partition 3.

Notice that partition 3 maps from where partition 2 left off to the end of the
disk (i.e. look at the start/end cyls.

The partitions created in the extended partition are commonly refereed to as
"logical partitions". In Linux you may have up to 11 logical partitions.

That is to say, in linux, your per disk partition limitations are:

	1 thru 4 are the primary, and among them the entire disk should be
	be mapped.

	Any disk cyl's not mapped via 1 thru 4 is not accessable.

	Any of 1 thru 4 may be flagged as an extended partition, but only 1.

	The extended partition can map partitions 5 thru 15.

	Note that the 1st logical partition is 5, EVEN IF you did not use all
	4 primary partitions (as in your case here).

	Any disk in the extended partition that is not mapped by a logical
	partition, is not accessable until it is. If you run out of logical
	partitions, then it is not accessible.

When the installer looks for disk space to lay down an install, the above are
the rules that it must follow. Therefore it will look for unmapped disk space,
and a partition id (or id's) to map that unmapped disk space.

Now, looking at your logical partitions (with minor rearrangement to make things
more obvious):

	> /dev/sda5            4718  -->   5961     9989120   83  Linux
	> /dev/sda6            5962  -->   8094    17133291   83  Linux
	> /dev/sda8            8095  -->  11918    30716248+   c  W95 FAT32(LBA)
	> /dev/sda7           11919  -->  12162     1951744   82  Linux swap

Suddenly, the reason for the installer's message is glaringly obvious. You do
not have any unmapped disk cylinders (as I suspected when I asked for your fdisk -l)

What you DO have is a 17 gb linux partition (#6) and a 30 gb windows partition (#8).

Some possibilities that you might consider:

     1)	using partition magic in windows, you might consider reducing the size
	of the windows partition.

     2) In Linux, it is possible to reduce the size of the FILESYSTEM on
	/dev/sda6, and then reduce the associated partition. It is a 2 step
	process (as just mentioned), and you must be very very careful in the
	2nd step (reducing the associated partition). I usually use fdisk to
	do this. The following are the caveats when using fdisk:

		- Since partition 6 is not the last partition, you will
		  necessarily need to delete partitions 6, 7, 8, and then
		  recreate them, with a filler partition between 6 & 7.

		- when 7 & 8 are recreated, they *must* be recreated with
		  exactly the same start/end cyl boundaries. Failure to do this
		  *WILL* result in catastrophic loss of any and all data in the

		- Since the new partitions that map what used to be partition 7
		  and 8 will most likely be different partition numbers, you MAY
		  need to make some adjustments in the original os's that
		  reference the original 7 and 8 partitions (since the partition
		  id's will most likely change).

Either of the above will yield free (unmapped) disk space that the installed can
then use for laying down a new install.

>  cfdisk -Ps
> FATAL ERROR: Bad primary partition 2: Partition ends in the final partial 
> cylinder

ignore the immediate above.

The rest is superfluous.

> # <file system> <mount point>   <type>  <options>       <dump>  <pass>
> proc            /proc           proc    nodev,noexec,nosuid 0       0
> # / was on /dev/sda5 during installation
> UUID=c2b10e6e-41fc-4fbd-bb7c-1a1974eaafd3 /               ext4    
> errors=remount-ro 0       1
> # /home was on /dev/sda6 during installation
> UUID=40436719-5fde-4f48-93f2-49457f0e1264 /home           ext4    defaults        
> 0       2
> # swap was on /dev/sda7 during installation
> UUID=03344fb4-f605-4675-92b9-090a48e88d0b none            swap    sw              
> 0       0

All the best,

- -Greg

- -- 

Please also check the log file at "/dev/null" for additional information.
                (from /var/log/Xorg.setup.log)

| Greg Hosler                                   ghosler at    |
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Comment: Using GnuPG with Fedora -


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