Date: Sat, 02 Oct 1999 23:30:35 +0800 From: Peter Wemm <peter@netplex.com.au> To: "Daniel C. Sobral" <dcs@newsguy.com> Cc: Marcel Moolenaar <marcel@scc.nl>, Daniel Eischen <eischen@vigrid.com>, des@flood.ping.uio.no, current@FreeBSD.ORG Subject: Re: new sigset_t and upgrading: a proposal Message-ID: <19991002153035.CA7CB1C03@overcee.netplex.com.au> In-Reply-To: Your message of "Sat, 02 Oct 1999 18:01:41 %2B0900." <37F5C9F5.6A2BA9AA@newsguy.com>
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"Daniel C. Sobral" wrote: > Marcel Moolenaar wrote: > > > > > But this still doesn't entirely solve the problem. You still have > > > to build and install a new kernel before installing the world. > > > While this is typically what most -current folks do anyways, it > > > still prevents backing up to a previous kernel after the install > > > world. > > > > You can easily install a kernel as part of the upgrade process. A > > complete upgrade would be something like: > > > > 1. Verify and/or install cross-compilation tools > > 2. Build world > > 3. Build kernel > > 4. Copy tools that are used by the install process > > 5. install kernel > > 6. install world > > 7. reboot > > > > If you install a kernel before installing world, you can easily recover > > when the install world fails: reboot. The new kernel is capable of > > running those binaries that got installed before the breakage. > > You missed the point. This is -current, right? You do all of the > above, and then reboot and find out that the new kernel doesn't > work. What do you do? The default procedure is to boot kernel.old. Read my lips: *NEVER* do a 'make world' until you've got a new bootable kernel. You can go back to a 'kernel.old' in 5 seconds. Undoing a 'make world' because a new kernel doesn't workd is a major drama. Just Don't Do It, at least not on -current where a kernel isn't expected to work every time. You can run a -current userland *months* behind your kernel, as long as you take care of libkvm and friends. Our kernel development process is done with backwards compatability in mind, not forward compatability. You can't expect last week's kernel to know about the new syscalls that are used after you committed to a buildworld. You can expect an old world to work though. Many people I talk with regularly go *months* between building world but on the other hand build a kernel every few days or so (including me). Don't use modules if you are doing this though, or keep a /modules and / modules.old to go with the kernel. (ie: when you do a 'make install' of the kernel, move /modules to /modules.old, mkdir /modules and then build/ install fresh kld's. Modules are only really useful in -current under certain curcumstances. Mostly this is 1) if you are developing a subsystem (eg: vinum) and need a rapid turnaround without a reboot, and 2) if you are running a fairly stable build, ie: not doing recompiles for months at a time. Especially don't use a vinum module (for example) if you're doing near daily kernel builds, use the static compilation option instead. Cheers, -Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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