> Matthew Ahrens wrote: > > Ross Newell wrote: > >> What are this issues preventing the root directory being stored on > >> raidz? > >> I'm talking specifically about root, and not boot which I can see > >> would be > >> difficult. > >> > >> Would it be something an amateur programmer could address in a > >> weekend, or > >> is it more involved? > > > > I believe this used to work with the old "zfs mountroot" setup with > > boot-from-UFS then root-on-ZFS. So, you could probably hack it back > > in, or just use the old bits. Lin or Lori could probably provide > more > > details, or correct me... > > > > > If you're using pre-build 62 bits, and the old > manual setup procedure documented in > > http://blogs.sun.com/tabriz/entry/are_you_ready_to_rumble > > a raidz pool can be used for booting. > > The zfs booter, in the current implementation, expects > to find these critical files: > > /boot/grub/menu.lst > /platform/i86pc/boot_archive > /platform/i86pc/kernel/unix > > in a dataset in a zfs pool and it can only access one > disk, so all of those files (and all blocks in those > files) need to be accessible on that disk. If the pool > is constructed of mirrored disks, that's OK, because > every disk in the mirror has ALL of the blocks for > every file in the pool. But if the pool is a RAID-Z > pool, the blocks will be distributed over multiple > disks and so the booter can't find them all. > > The reason RAID-Z worked in the older implementation > is that the system wasn't really booted off zfs. It was > booted from a ufs file system, and then a zfs dataset > was mounted as root. That was useful as a prototype, > but not optimal for the long run because it required > a separate slice to be allocated for the ufs boot file system. > > Ultimately, we expect to support booting from RAID-Z > by implementing some kind of "replicate on all devices > in the pool" option for bootable datasets. But that > option doesn't exist yet and it's a ways down on the > priority list at this time. > > Lori
I don't understand why support for mountroot was dropped in build 62; it was working fine for my raidz2 root pool, I just had to bootstrap it from a small UFS filesystem on a USB flash disk. Now I have tried to upgrade to build 70 and I get an error saying that zfsroot in /etc/system is not supported anymore. This machine has 4 disks and no space for more disk... and I don't feel like repartitioning to accommodate a mirror for /root. Lori, what do you suggest I should do? I could just keep all of root minus /usr, /var, etc.. on the usb thumb drive? and mount the rest from the raidz2 pool... Is that the only clean way to do it? Regards, Kugutsumen _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
