On 8/26/07, Abe Skolnik <abe_skolnik@xxxxxxxxx> wrote: > Dear Mr./Dr. Williams, > Just "Dan" is fine :-) > > Because you can rely on the configuration file to be certain about > > which disks to pull in and which to ignore. Without the config file > > the auto-detect routine may not always do the right thing because it > > will need to make assumptions. > > But kernel parameters can provide the same data, no? After all, it is > not the "file nature" of the "config file" that we are after, > but rather the configuration data itself. My now-working setup uses a > line in my "grub.conf" (AKA "menu.lst") file in my boot partition that > says something like... > "root=/dev/md0 md=0,v1,/dev/sda1,/dev/sdb1,/dev/sdc1". > This works just fine, and will not go bad unless a drive fails or I > rearrange the SCSI bus. Even in a case like that, the worst that will > happen (AFAIK) is that my root-RAID will not come up and I will have to > boot the PC from e.g. Knoppix in order to fix the problem > (that, and maybe also replace a broken drive or re-plug a loose power > connector or whatever). Another MD should not be corrupted, since they > are (supposedly) protected from that by supposedly-unique array UUIDs. > Yes, you can get a similar effect of the config file by adding parameters to the kernel command line. My only point is that if the initramfs update tools were as simple as: mkinitrd "root=/dev/md0 md=0,v1,/dev/sda1,/dev/sdb1,/dev/sdc1" ...then using an initramfs becomes the same amount of work as editing /etc/grub.conf. > > So I turn the question around, why go through the exercise of trying > > to improve an auto-detect routine which can never be perfect when the > > explicit configuration can be specified by a config file? > > I will turn your turning of my question back around at you; I hope it's > not rude to do so. Why make root-RAID (based on MD, not hardware RAID) > require an initrd/initramfs, especially since (a) that's another system > component to manage, (b) that's another thing that can go wrong, > (c) many systems (the new one I just finished building included) do not > need an initrd/initramfs for any other reason, so why "trigger" the > need just out of laziness of maintaining some boot code? Especially > since a patch has already been written and tested as working. ;-) > Understood. It comes down to a question of how much mdadm functionality should be duplicated in the kernel? With an initramfs you get the full functionality and only one codebase to maintain (mdadm). [snip] > Sincerely, > > Abe > Regards, Dan - 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
