Am Montag, den 10.08.2009, 13:31 +0200 schrieb Robert Millan: > On Sat, Aug 08, 2009 at 07:13:20AM +0200, Felix Zielcke wrote: > > Am Freitag, den 07.08.2009, 21:22 +0200 schrieb Robert Millan: > > > On Fri, Aug 07, 2009 at 04:29:00PM +0200, Felix Zielcke wrote: > > > > Am Freitag, den 07.08.2009, 13:27 +0200 schrieb Robert Millan: > > > > > On Wed, Aug 05, 2009 at 08:18:29AM +0200, Felix Zielcke wrote: > > > > > > Am Dienstag, den 04.08.2009, 23:19 +0200 schrieb Robert Millan: > > > > > > > On Fri, Jul 31, 2009 at 06:26:51PM +0200, Felix Zielcke wrote: > > > > > > > > > > > > > > > > If we'd do an arbitrary mapping then `grub-probe -t drive' > > > > > > > > would show > > > > > > > > the wrong grub device. > > > > > > > > But except from this I think that would be okay. > > > > > > > > > > > > > > We can never garantee that `grub-probe -t drive' will show the > > > > > > > "right" drive, > > > > > > > at least on i386-pc, because we don't know how is BIOS going to > > > > > > > order them. > > > > > > > > > > > > Yes drive not, but the partition. > > > > > > > > > > It's true, but we don't really make the distinction. UUID search > > > > > will find > > > > > a filesystem, which is in a partition (usually), and doesn't rely on > > > > > partitions > > > > > being reliable. > > > > > > > > > > That's fortunate! It means we don't have to commit to partition > > > > > numbers being > > > > > reliable, even if they are right now. > > > > > > > > > > Because of this (unless I missed something), at the end of the day the > > > > > unreliability issue you described doesn't translate into any real > > > > > problem > > > > > for us. It just adds more to a problem we already solved. > > > > > > > > > > > Unfortunately we don't have UUID support on every filesystem we > > > > > > support > > > > > > like JFS. But I think it's not that commonly used. > > > > > > > > > > Adding UUID support to new filesystems is very easy. I did the first > > > > > ones > > > > > with just 5-10 minutes of research and a few lines of coding. > > > > > > > > > > Would you like to do JFS ? > > > > > > > > I did it now for JFS. > > > > > > > > I tried it now out with dos_part set to p + 2 with my find_by_uuid patch > > > > and now I get a `no such partition' error on my dmraid device. > > > > So we can't use an arbitary mapping in grub_util_biosdisk_get_grub_dev > > > > > > Why not? > > > > well then we would need to change the partition table parsing code to > > use the same arbitary mapping for GRUB_UTIL && LINUX then > > grub_util_biosdisk_get_grub_dev and I think that's not really a proper > > solution. > > Why? In that specific situation, it seems: > > - We're unable to obtain partition numbers reliably > > - It doesn't matter, because the upper layer will sort that out
Well with the current design of util/hostdisk.c it doestn't work. I don't know how we can make an arbitary mapping work. > Though, it'd be much better if we could obtain this information from Linux. > Did you figure out if the behaviour of that ioctl is a bug or is intentional? Probable intentional, because device-mapper is also used for LVM for which HDIO_GETGEO really doestn't make sense. Someone sent a patch to implement it for device-mapper in 2006 to LKML [0] but it wasn't accepted. Now I noticed Andrew Morton said `block_device_operations now has a standalone `getgeo' method.', which doestn't say me anything if this is something we can use or if this is purely internal for the kernel. [0] http://lkml.indiana.edu/hypermail/linux/kernel/0602.1/index.html#0729 -- Felix Zielcke Proud Debian Maintainer _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
