install gparted on Ubuntu 8.10

lazer100 lazer100 at talktalk.net
Fri Sep 28 18:03:09 UTC 2012


On 26-Sep-12 17:29:52 Nils Kassube wrote:
>lazer100 wrote:
>> On 17-Sep-12 23:19:49 Nils Kassube wrote:
>> >If you use e.g. gparted it will automatically format the partitions
>> >according to the selected file system
>> 
>> you can select "unformatted" as the formatting option with gparted on
>> 8.10,
>> 
>> but it only shows this option for formatted partitions if you first
>> delete the partition and then create a new one.
>> 
>> this option isnt shown if you reformat an already formatted one.

>That's interesting - I never noticed that option.

>> I used this in order to zero the drive, as there were some problems
>> zeroing an already formatted one as I think the zeroing interferes
>> with the file system,
>> not sure.

>Sure it interferes with an existing file system - if you zero a 
>partition, you REMOVE the file system.

I guess one should only zero an "unformatted" partition,


>> > but if you use good old fdisk, it
>> >will only write the partition table and not format anything. And if
>> >you overwrite a partition with zeroes, like the OP wanted to do, it
>> >is also not formatted afterwards.
>> 
>> this not being formatted afterwards leads to some problems!

>Right, depending on the data already existing in the space now used by 
>the newly created partition entry it may look like a valid file system 
>probably with lots of errors.

directly accessing sectors of a filesystem does have its uses,
namely to do a sectorwise backup, eg I do sectorwise backups of Windows C:\ 
on Linux using dd, that way I can restore verbatim the Windows system
if there are problems. This of course will only run on the existing PC
not on other PC's, you'd have to reactivate Windows if you tried to
use that on another PC, as also is the case if you tried to reuse the
system drive on another PC.

but the zeroing would seem to be an inadvisable use of dd 
for a volume formatted for some file system.

ie one dabbles with low level use of dd at one's own risk!

perhaps they should put a warning message if you do such


>> so I needed to unformat the drive initially
>> with gparted as mentioned above,
>> 
>> another problem which happened was that when you delete and reformat
>> as unformatted, the partition numbering changes, which makes it more
>> effort to keep track of which ones had been zeroed.
>> 
>> 
>> I managed to get them into ascending numbers, but with some numbers
>> missing,

>The numbers are always 1 to 4 for the primary partitions and from 5 
>upwards for logical partitions inside the extended partition. So if you 
>only have one primary partition you can't have the remaining numbers 
>below 5. But from 5 upwards there shouldn't be any numbers missing.

in that case there wasnt a problem, I think it was

1
5
6
7
...
16

where 1 is the extended partition,

I guess that has advantages over just numbering 1 2 3 4 5 6 7 regardless
as it will be more stable to changes, ie changing the primary partitions
I think wont change the logical partition numbering.


>> I dont know if there is any way to renumber the partitions,
>> so they ascend sdc1 sdc2 sdc3 ....

>I think you could use fdisk and first delete all partitions and then 
>create new entries with the same geometry and partition type as the 
>partitions you have now but in the wanted order. However it is very 
>error-prone and I would avoid it if at all possible. OTOH, as long as 
>you are playing with an empty disk there shouldn't be a real problem. :)

>> one other problem I had is that one mustnt zero the extended
>> partition as its not a proper partition!

>Right. If you zero the extended partition you loose all logical 
>partitions inside the extended partition ...

another thing to not do with dd!

I have some further questions as regards this drive, but as its
a slightly different theme I will start that as a new topic,
the subject line is about sector testing, if you have any ideas
on that please reply on that topic,







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