On Tuesday, 3 April 2007 18:34, Stefan Seyfried wrote: > On Tue, Apr 03, 2007 at 05:55:21PM +0200, Tim Dijkstra wrote: > > Hi, > > > > I've got a bugreport [0] from a user trying to use raid and uswsusp. He's > > using initramfs-tools available in debian. I'll describe the problem > > and my analysis, maybe you can comment on what you think. A warning: I only > > have a casual understanding of raid, never looked at any code related to it. > > > > This is a setup where root maybe on raid, but swap isn't. Swap on raid > > will be very difficult to support, I think. > > "it depends" :-) Theoretically (and I mean it), we can do that. > > Now comes a crucial point. The script that finds the raid array, finds > > the array in an unclean state and starts syncing. > > bad. Don't do that. Data will be lost. > > > After this, resume finds an image in the swap partition and starts the > > resume process. Part of this process is freezing everything but itself, > > which fails on the process/thread that does the syncing. > > > > IMO, the problem comes from the fact we started syncing, before we could > > start resume. > > Yes. > > > Now the problem could theoretically be solved by not starting the > > assembly of the array once it is discovered, but modifying the > > initramfs to do the assembly after we have had the chance to resume. > > Yes. > > > The debian-maintainer of mdadm thinks that the suspend process should > > have left the array in a clean state, but this is IMHO impossible. We > > are freezing userspace. A mdamd process looking after the array will > > probably get into trouble if we come back from suspend and we have > > done something to the array in the mean time. > > Yes. > > > What do you think? > > You are right, he is wrong. > Do not touch anything before resume. Definitely. The same applies to the built-in swsusp, BTW. - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
