Re: install/39697: no raidframe support in sysinst

[Greg Oster <oster%cs.usask.ca@localhost>]

The following reply was made to PR install/39697; it has been noted by GNATS.

From: Greg Oster <oster%cs.usask.ca@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: Bernd Ernesti <pr200817%veego.de@localhost>
Subject: Re: install/39697: no raidframe support in sysinst 
Date: Tue, 07 Oct 2008 19:42:33 -0600

 Bernd Ernesti writes:
 > The following reply was made to PR install/39697; it has been noted by GNATS.
 > 
 > From: Bernd Ernesti <pr200817%veego.de@localhost>
 > To: gnats-bugs%NetBSD.org@localhost
 > Cc: 
 > Subject: Re: install/39697: no raidframe support in sysinst
 > Date: Sun, 5 Oct 2008 12:08:46 +0200
 > 
 >  On Sun, Oct 05, 2008 at 12:05:04AM +0000, Martin Husemann wrote:
 >  >  On Sat, Oct 04, 2008 at 08:30:00PM +0000, Bernd Ernesti wrote:
 >  >  >        sysinst has no obvious option (if at all) to create a raid with
 >  raidframe
 >  >  >        and install the system on it.
 >  >  
 >  >  Not that I disagree with the wish to have more complete support in sysins
 > t -
 >  >  just for the record, the unobvious option is:
 >  >  
 >  >   - use the utility menu and run a shell from there
 >  >   - use raidctl to configure your raid set
 >  
 >  Unfortunally this is not so easy.
 >  
 >  IMHO it is missing the fdisk / disklabel part (fstype RAID), which is a requ
 > iremnt
 >  for creating the raid set and the initial setup of the bootloader for a root
 >  raid
 >  set.
 >  
 >  And I'm not sure which stripe size I should use for a raid1 set.
 >  Greg used a formular on how to calculate it in his mail on current-users at
 >  the end of August 2008:
 >   ($stripewidth / 2 * ($disks - 1)) == MAXPHYS
 >  But it looks like that was an example for a raid5 set, so I'm not sure about
 >  the '($disks - 1)' part and if it applies to a raid1 set too.
 
 The math works for a RAID 1 set as well -- with MAXPHYS at 64K you want
 a stripe width of 128 blocks ...
 
 >  >   - exit the shell, go back to the sysinst main page and start the install
 >  >   - raid0 (or whatever you created) will now be offered as an install 
 > target
 
 Even installing to "half a RAID 1 set" would be a step in the right 
 direction...  I'd argue, in fact, that we should only attempt to 
 support installing to a RAID 1 or half of a RAID 1 set...  We can't 
 boot from RAID 0 or RAID 5, so those could be just ignored for the 
 purposes of sysinst...
 
 I'm happy to provide whatever support I can towards sysinst installing
 to a RAID 1 set...
 
 Later...
 
 Greg Oster