Re: GPT, wedges and RAID-1 on new server with NetBSD 7

[Gerard Lally <gerard.lally%gmail.com@localhost>]

On Tue, 08 Mar 2016 15:06:32 -0500
Greg Troxel <gdt%ir.bbn.com@localhost> wrote:
> 
> Gerard Lally <gerard.lally%gmail.com@localhost> writes:
> 
> > If I want separate / swap and /home, I presume I should delete raid1a
> > and create raid1a, raid1b and raid1e instead (by clicking on its
> > parent raid1 and selecting "Edit BSD partitions")?
> 
> Separately from how to use sysinst for this (which I've never done), I
> think it is sensible to have partitions within a raid.   I typically
> have wd0a/wd1a as type raid, being mostly the whole disk, and then
> within raid0 have a/b/e/f.
> 
> > I create these and proceed with installation as normal, selecting
> > raid1 as the available disk on which I want to install NetBSD. But
> > each time I do this I get the dreaded error "FATAL: No bootable medium
> > found! System halted."
> >
> > Where am I going wrong? One thing I note is that I am not asked at any
> > point to install bootcode to the disks as I would be with non-RAID
> > setups.
> 
> Probably you can boot to utility and run installboot manually on wd0a/wd1a.
> 
> > If it's not possible to do this with sysinst is it at least possible
> > to do it by dropping to a shell?
> 
> When I want to set up a new raid system, I tend to get a bootable disk
> with a minimal system and boot that and do the whole disk setup
> including bootblocks by hand.  But I suspect you are just missing
> bootblocks.
> 
> > Ideally I would like to use GPT with the RAID-1 setup as well, since I
> > will be on 2 x 2TB disks and I anticipate this getting bigger, not
> > smaller in years to come. I have successfully set up NetBSD with GPT
> > by dropping to a shell but I don't know where to add RAID into that
> > mix.
> 
> As others commented it seems disklabel-in-raid-in-gpt works.  So that
> leads to having two raid sets.  One is small enoguh to fit in 2T, and
> would have root, swap, /var, /usr sorts of things.  The other would be
> just bare raid in gpt, and have a filesystem in raid0d.  or maybe gpt
> inside raid.  The point is that the >2T raid doesn't have a disklabel
> (because it's too big) and doesn't have root (because the bootblocks
> can't yet find it).

Well I successfully booted a RAID system in Virtualbox yesterday
evening! I followed Tobias's instructions, and also found David
Brownlee's wedgeraidbootsetup.sh script** very useful. It's a lot
clearer to me now what has to be done.

Here is an overview for anyone else having trouble understanding the
steps:

1) create a small gpt partition on disk0 and disk1 for boot;
2) create another gpt partition on disk0 and disk1 for raid;
3) assemble the raid using the components created in 2;
4) use gpt again to partition this raid array into / swap and home
partitions;
5) build filesystems on these partitions;
6) mount the filesystems and extract sets;
7) install boot on the wedges created in step 1;
8) configure the system (fstab, rc.conf, etc)

I'm happy again now! I was afraid I might end up having to install "An
Inferior Operating System" on my 36 euro per month server!

;-)

Thank you one and all for helping me understand this.

** Posted to netbsd-users June 2015:
https://mail-index.netbsd.org/netbsd-users/2015/06/16/msg016252.html

-- 
Gerard Lally