From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.1) Gecko/20031030 Description of problem: While I was fresh installing FC1; it alaramed me of a low swap partition size (50MB) than the memory on the system (512MB) I decided to make a swap of 512MB so I highlighted the old 50MB partition (/dev/hda7) and hit delete. After it was deleted I found that my Gentoo partition number (/dev/hda8) has been changed (/dev/hda7) This is a bug since this partition was already created and has a fully running system of Gentoo. And I mount my partiotns using device numbers rather than partiotn labels. Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1. Follow steps above 2. 3. Actual Results: partition /dev/hda8 became /dev/hda7 Expected Results: /dev/hda8 to remain as it is /dev/hda8 Additional info:
It's worse than that. What seems to be happenning is that Disk Druid is numbering partitions according to the order they were created, not the order they physically appear on the disk. Some software (earlier versions of Partition Magic: I don't have later ones to check) considers this a straight bug. Fedora fdisk prints a warning message. This could bite users later: any software that re-writes the partition table is likely to renumber partitions into physical order, EVEN IF no partitions were added or deleted. At that point, any software relying on knowing physical partition numbers will have their partitions renumbered under them. The poor user, meanwhile, certainly hasn't touched his or her partitions, and won't understand why a partition seems to have "gone" (when it's actually just "moved"). In my case, I deleted and recreated my /var and /usr, and they were recreated as hda10 and hda11, moving a FAT32 partition from hda11 to hda9. Fortunately, this doesn't worry Windows, but only because there isn't an OS on that drive. In this case, the FAT32 partition will end up being moved back to hda11 at some point: the number changes twice, when it needn't and shouldn't move at all.
This e-mail from Linus is about USB device numbering, but it's the best exposition of which I know of the principle that numbering should not be based on history: http://lwn.net/1999/0603/a/lt-usb.html
Logical partitions inside an extended partition don't have an included number within them and just change based on the order they're written in the extended partition table (which has no guarantees on ascending vs otherwise).