Re: raidframe with R5/RS not reconstructing?

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

On Tue, 21 Feb 2012 00:39:11 -0800
Brian Buhrow <buhrow%nfbcal.org@localhost> wrote:

>       Would it be possible to get a pullup to NetBSD-5.x as well?

Yes.  Request just sent.  Thanks for the reminder.

Later...

Greg Oster

> On Feb 20,  4:46pm, Greg Oster wrote:
> } Subject: Re: raidframe with R5/RS not reconstructing?
> } On Thu, 16 Feb 2012 15:09:40 -0600
> } Greg Oster <oster%cs.usask.ca@localhost> wrote:
> } 
> } > On Sun, 12 Feb 2012 06:50:52 -0600 (CST)
> } > "John D. Baker" <jdbaker%mylinuxisp.com@localhost> wrote:
> } > 
> } > > An experimental oversight caused one unit of my raid to get
> marked } > > as failed, even though nothing's wrong with the
> hardware.  It's now } > > running in degraded mode and all the data
> appear to be intact. } > > 
> } > > No problem, I thought.  'raidctl -R /dev/wd8a raid0' should put
> it } > > back to its old self.
> } > > 
> } > > But it doesn't.  It immediately reports 12% completion and sits
> } > > there (almost 9 hours now) with no apparent progress and no ETA
> } > > computed (00:00).
> } > > 
> } > > I suppose this is the acid test for the little-used RAID 5
> w/Rotated } > > Sparing option.  The last time I needed it (in
> NetBSD-4 days on } > > sparc), it worked just fine.
> } > >
> } > 
> } > For those playing along at home:  
> } > 
> } > I am able to replicate the issue, and have an understanding of
> what } > the problem is (basically, with rotated sparing every nth
> stripe of an } > n-disk RAID5_RS set doesn't generate any writes
> during reconstruction, } > and the logic in the code is expecting
> there to be writes for every } > stripe). 
> } > 
> } > Just a simple matter of finding the correct fix... 
> } > 
> } > (the reason this worked back in NetBSD-4 days is that the
> } > reconstruction map code has been reworked since then, and this bug
> } > was introduced...)
> } 
> } The following two changes fix this issue:
> } 
> } cvs rdiff -u -r1.33 -r1.34 src/sys/dev/raidframe/rf_reconmap.c
> } cvs rdiff -u -r1.117 -r1.118 src/sys/dev/raidframe/rf_reconstruct.c
> } 
> } A request for a pullup to netbsd-6 will happen in the next little
> } while...
> } 
> } Later...
> } 
> } Greg Oster
> >-- End of excerpt from Greg Oster
>