[arch-general] fdisk vs cfdisk... And is my drive borked or what?

Mauro Santos registo.mailling at gmail.com
Thu Mar 18 00:48:00 CET 2010


On 03/17/2010 10:45 PM, Linas wrote:
>> Which complained about a dos compatibility flag and that I should
>> change the display/entry units to sectors. This showed me a small bit
>> of unused
>> space above my last logical partition (/dev/sda12)...

Don't worry about that for now, that could only come back to bite you if
you had a new disk with 4KB sectors (or an SSD that I think prefers
writes to be aligned with pages ... or something like that).

>> =>  FATAL ERROR: Bad primary partition 3: Partition ends after
>> end-of-disk
>> =>                                   Press any key to exit cfdisk

cfdisk can complain if _anything_ isn't as it wants it to be. cfdisk is
easier to use than fdisk but complains a lot if the partition table
deviates a little from the most compatible "format" possible.


>> Because that's my extended partition... And a close look at the ending
>> cylinder/sector of /dev/sda4 is a slightly higher number than it reports
>> the total cylinders/sectors to be...

I take it that the first listing is in sectors, if you look closely you
will see that your last partition (swap) end before the end of the disk
so you're safe, the extended partition is just a placeholder for other
partitions, so if the partitions do not try to use space that doesn't
exist it should be ok. However I would still try to rectify the ending
of the extended partition. Backup all your data and try to shrink that
extended partition until it fits in your disk.

> I find an oddity on your paritition table, though. You say that
> /dev/sda4 is an
> extended partition (and you do have logical partitions) but it is listed
> by fdisk as
> having type 0xf (W95 Ext'd (LBA)) instead of 0x5 (Extended). I suspect
> that after
> testdisk restoring, some old entries got loaded?
> If that's really a wrong entry, you can do the fdisk delete/recreate tip
> to force its
> length to be inside the disk limits. However, fdisk won't allow you to
> set a partition
> type of 5, which is a pity when you *really* know what you are doing.

Type 0xf is also ok, it all depends on which program created the
partition table initially, I'm not sure but I think gparted used to set
extended partitions to 0xf and so do many other programs.
fdisk should be able to change the type to 5 but if it can't then give
sfdisk a try but make sure all your data is safe.


More information about the arch-general mailing list