[parted-devel] "Error: Can't have a partition outside the disk!"

[Jim Meyering]

Phillip Susi wrote:

> On 09/19/2010 02:00 PM, Jim Meyering wrote:
>> Hah ;-)
>> When something like that goes wrong,
>> it never feels like a "slight" problem.
>
> Surprisingly I've seen a lot of people with a slight overlap at the
> end of a partition that never causes a problem since it is never
> actually accessed.  They can boot and access the partitions just fine;
> it's only (g)parted that appears to have a problem.  Of course, once
> asked for an fdisk -lu, the problem can be seen and fixed.
>
>>> do anything with it, and they have to resort to fdisk to get a look at
>>> the table, figure out what's wrong, and fix it.  It would be much
>>> preferable if (g)parted would let you know something is wrong, but
>>> continue with showing you what's in the table and letting you fix it.
>>
>> That sounds sensible.
>> Perhaps an option to remove (non-interactively) any partition with
>> an "invalid" extent.  We could start by removing any partition that
>> extends beyond (or "too close to", depending on the partition table
>> type) end of disk.
>>
>> Do you feel like working on this?
>
> Automatic removal of partitions is absolutely not something that
> should be done.  Not allowing you to create a broken partition is
> good, but when one already is, tools should just notify of the problem
> and leave fixing it up to the user.  That is why I suggested simply
> changing the error flags to allow ignoring it.  The usual method to
> fix the problem I outlined above is to adjust the partition end point
> to trim off the last bit that is overlapping, rather than to destroy
> the entire partition, after backing up all retrievable contents of
> course, and then forcing a fsck.

If that really such a common scenario?
What tool/scenario seems to cause the trouble?

Perhaps parted should provide a way to fix it via
a low level partition-resize command,

  partition-resize N START END

Where you might use

  partition-resize 3 +0 -50s

in order to shrink the 3rd partition by 50 sectors.

Note: this is in contrast with the "resize" command,
which also operates on file systems, but that is now deprecated.
The proposed new command would touch only the partition table.