Re: current best practice for booting >2TiB volumes?

[eric%cirr.com@localhost (Eric Schnoebelen)]

David Laight writes:
- On Fri, Feb 18, 2011 at 06:28:34PM -0500, Matthew Mondor wrote:
- > On Fri, 18 Feb 2011 12:09:39 -0600
- > eric%cirr.com@localhost (Eric Schnoebelen) wrote:
- > 
- > > When I attempt to boot (after relocating wd2/3 to wd0/1), the gpt
- > > mbr loads bootxx_ffsv1, but bootxx_ffsv1 complains it can't find
- > > /boot in the root filesystem.
- 
- The bootxx code probably requires that to root fs be at the start of
- the raid volume.

Hmm, that might be the problem.  I was treating it like a wdXa,
where the NetBSD partion starts at 64 (offset 63).  I'll try
recreating the FS with root starting at offset 0.

- It might also get confused by any disklabel in the pbr (presumably
- you don't have one).

installboot(8) does complain about there being no pbr..

- Certainly 'boot from RF' relied on the bootxx code adding in 64 sectors
- and trying again after an initial file open failed.
-
- But I can't remember if this was in any way related to detecting
- an RF entry in the pbr's disklabel.
- 
- Your disks may have larger physical sectors. So you really want
- to align the fs fragments/blocks onto physical sectors. The offset
- 63 sector offset (one nominal track) isn't a good value!

I was reading that as offset of 63, with sectors 0-63 (aka 64)
being unused, and sector 64 being the first sector of my
partion.

Am I mis-interpreting?

- 
- > Is your FS really an FFSv1 one?  Otherwise you will probably want to
- > install the bootxx_ffsv2 loader instead.  FFSv2 supports larger file
- > systems than FFSv1, but of course that might not be a problem for
- > your / ...
- > -- 
- 
- Actually FFSv1 supports  disks with more than 2^32 sectors - you just
- have to increase the fragment size so that there are less than 2^32
- (or maybe 2^31) fragments.

That's not a worry, the GPT partition in question is about
10Gb..

Thanks!
        Eric


--
Eric Schnoebelen                eric%cirr.com@localhost          
http://www.cirr.com
  "Turns out a severe caffeine deficiency and crushing deadline pressures
      have conspired to render me temporarily stupid."   - Larry Chin