mlh%goathill.org@localhost (MLH) writes: > I'm looking at exactly how to set up a couple of 4G disks in a > bootable gpt/raid1 (raidframe, BIOS boot) configuration. I have a > temporary 80G boot drive I'm currently working from. It is currently > running NetBSD 8.99.17 > > I am attempting to follw the instrucitons in GPT(8), > https://www.netbsd.org/docs/guide/en/chap-rf.html#chap-rf-intro > https://wiki.netbsd.org/users/mlelstv/using-large-disks/#index6h1 > > Things are generally going well but before I actually install a > system, one question I have is how to make the configuration > bootable. > > - GPT(8) says to make a bootable partition using gpt but doesn't > mention doing that with raid > > - NetBSD Raid guide says to install the bootloader onto one > (preferably both) of the raid units but isn't using gpt on large > disks. I am not really sure, but some advice: Generally, the way booting on raid works is that (with a little bit of fuzz because I amy be off on details) it is limited to RAID-1, where therefore each disk is a copy (if you only read) the MBR or first-stage boot is in the normal place for the disk the 2nd-stage boot, blocks 2-15, are in the partition that is labeled bootable the bootable partition is of type RAID, and on those, the first 64 sectors are the raid header (except for 0/mbr, 1/disklabel, and 2-15/bootxx, so really latter 48 of first 64). Then, the fs that exists within the RAID-1 starts. the 2nd-stage boot code is able to figure out that the boot parttion is of type raid, not ffs, and then does addr += 64 and tries again. I am unclear on if it recognizes the raid header, fails to recognize ffs and tries blindly, or looks at the type. therefore, I would expect two disks, each gpt gpt disk-level boot setup normally with a gpt partition of type raid in those, bootblocks at front and included ffs, via raid-1 init set up to boot the raid parittion as if it were ffs hope for the best and debug to be a reasonable strategy.
Attachment:
signature.asc
Description: PGP signature