----- Original Message ----- > From: "Josh Boyer" <jwboyer@xxxxxxxxxxxxxxxxx> > To: "Fedora Cloud SIG" <cloud@xxxxxxxxxxxxxxxxxxxxxxx> > Cc: "Colin Walters" <walters@xxxxxxxxxx> > Sent: Wednesday, August 26, 2015 2:09:23 PM > Subject: Atomic Host and the kernel > > Hi All, > > I'm emailing my questions on the topic here as it seems to be the best > Fedora focused place to discuss Atomic Host and kernel interaction. > If that isn't the case, please point me to where you believe that is. atomic-devel@xxxxxxxxxxxxxxxx is another good place > > I have two basic questions around the interaction of Atomic Host and > the kernel. The first is fairly straightforward: is there anything > Atomic Host or the atomic toolset needs that the kernel does not > provide today? Missing features, bugs that have been hit but not > fixed, etc. I believe the answer is likely no, given that atomic is > off and running fine and leverages hardlinks but I thought I would > ask. I don't think so -- I haven't heard of any such needs... > > The second question is a bit more involved. Atomic provides the nice > ability for rollback across the entire OS tree. However, that > requires an atomic image to be spun for every instance of that tree. > That, naturally, means that whenever a new Atomic Host instance is > spun it will use whatever kernel happens to be the latest in the > Fedora release it is built from. This means that one cannot leverage > the nice side effect of being able to update the kernel independently > of userspace. (Which is also nice from a testing perspective when it > comes to kernels and regressions.) > > To my understanding, the only way to provide such testing would be to > create Atomic Host images that only deviate from the official images > in that they provide a new kernel. Then one could use the standard > atomic tools to do testing and rollback of _only_ the kernel if a > problem is detected. While this is certainly possible, I'm not sure > it is something the Cloud sig (or whomever) is really interested in > doing. On the kernel side, we could provide such images built on our > own but I'm not sure the effort or duplication of > tooling/infrastructure is worthwhile overall. Particularly when > non-atomic Rawhide continues to be flexible enough for these purposes. My first thought is that the kernel in an atomic host should just work, dammit! :) There could be different trees reflecting different levels of kernel maturity. If it's to be one tree, multiple kernels shipping together, as you mention below, might be the best option -- there's still a grub menu, for choosing, but I'm not positive if there'd be a conflict w/ any ostree rollback fu. Jason > > With a two week image release timeframe though, being able to use > different kernels might be a good idea. Does anyone have any thoughts > around this topic and how to possibly accomplish such testing? The > only other idea I had was to spin the Atomic Host images containing > the last 3 kernels in them, but I am not sure if choosing between them > at boot is currently possible with multiple kernels installed. > > Thanks in advance. > > josh > _______________________________________________ > cloud mailing list > cloud@xxxxxxxxxxxxxxxxxxxxxxx > https://admin.fedoraproject.org/mailman/listinfo/cloud > Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct > _______________________________________________ cloud mailing list cloud@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/cloud Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
