Subject: Re: raidframe: machine hangs when starting reconstruction
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Greg Oster <oster@cs.usask.ca>
List: current-users
Date: 05/22/2000 19:00:11
Manuel Bouyer writes:
> Another odd thing I noticed on this machine: if I power a disk down, it's
> maked as failed and the box continue running without problem. I can
> power if back up and dd from it without problem. But when I start
> a reconstruction (raidctl -R) the machine hangs for several 10s of seconds.
> In this time there's a lot activity on the non-failed disk of the raid1 *only
> *
> (looking at the led I think it's running at full rate). Then the recontructio
> n
> starts (both led of disks start blinking) and the machine unwedges.
> Any idea ?

The first thing RAIDframe does before a reconstruction is to achieve 
'Quiescence' -- to make sure that it's got all it's pending writes
get flushed out to disk.  Now unless the machine is fairly 'busy' at the time
(or it's a slower machine?) I wouldn't expect this to freeze things for
several 10s of seconds...

> PS: I can't enter ddb because I didn't find how to do it on an alpha
> with serial console. a break doesn't semm to work ...

I don't know the answer to that one :-/

Later...

Greg Oster