On Tue, 2009-04-28 at 17:04 -0700, H. Peter Anvin wrote: > Daniel Reurich wrote: > > > >> For this to be reliable, there is only one sensible configuration, which > >> is for /boot to be a RAID-1, which is better handled by -- guess what -- > >> partitioning systems; and we already have quite a few of those that work > >> just fine, thank you. Otherwise there WILL be configurations -- caused > >> by controller failures if nothing else -- that simply will not boot even > >> though the system is otherwise functional. Promoting this kind of stuff > >> is criminally stupid. > > > > I disagree. Grub is quite capable of booting from and assembling a > > raid5 volume and accessing it's partitions contents, even if the array > > is degraded. All I'm asking for is that the first 64 kbytes of the disk > > be reserved and some of it possibly (but not necessarily) replicated so > > that a bootloader capable of assembling a raid array can be installed on > > the start of each member disk so that whatever disk the bios decides to > > boot from, it will always boot. > > > > Grub is capable of doing that IF THE FIRMWARE CAN REACH IT. Well if the firmware can't find one if the disks, then it doesn't matter what scheme we have. Even a single disk won't work. > > You seem to have the happy notion that this is something typical, which > frequently isn't the case. I'd say it's typical of 100% of pc's, mac's and just about anything else that boots of a harddisk without a hardware raid controller. > > What's worse, you're clearly of the opinion that this is something that > should be promoted to users, which is the "criminal" part of "criminally > stupid." I'd like it for me, and to prove it can be done and is a cleaner and less administratively intensive way of doing it then teaching the OS/user how to partition a disk and add each partition to into their respective raid array each time they need to replace or add a new disk to their array(s). Whether this proves reliable and stable enough to be promoted to users can only be seen once it's proven (or not). What's your beef. MD already reserve some space for the superblock, and write-intent bitmap (which I believe is also replicated across the member disks), so why not add some space to this to make it possible for a bootloader as well. -- Daniel Reurich Centurion Computer Technology (2005) Ltd Ph 021 797 722 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
