On Thu, 8 Sep 2011 15:13:55 -0400, Canek Peláez Valdés wrote about Re: [gentoo-user] /dev/sda* missing at boot:
> On Thu, Sep 8, 2011 at 2:05 PM, David W Noon <dwn...@ntlworld.com> > wrote: [snip] > > I don't know if the kernel offers any particular blessing to any > > hotplug handler. > > udev is the device manager for the Linux kernel. It replaced devfs. One can use mdev just as readily as udev. > It's related, but doesn't (necessarily) need to be the same that the > user space part. > > Yeah, udev is mandatory in the kernel, unless you use a traditional > /dev directory. But udev isn't actually part of the kernel. Only hotplug support is actually in the kernel. The udev daemon is started during the sysinit run-level and it connects itself to hotplug support. [snip] > >> Dracut automatizes this. Is a non-problem. > > > > If dracut actually worked ... > > What doesn't work for you? Since dracut is not yet stable, I don't have any problems with it because I don't use it. But it does have quite a few open bugs in Gentoo's Bugzilla, and I suspect many more in other distro's bug trackers. > > During the "do stuff" phase, /usr is also writeable, which is > > undesirable on production systems. That's the *original* problem > > with merging a read-only /usr with /. [We seem to be going in > > circles with this one.] > > It's the same when you upgrade the system. If you don't allow rw in > /user *ever*, then you are not allowed to upgrade. Which I was chewed > up because I said it was an alternative. Production systems have strictly scheduled change-control windows, usually only once or twice a year. Having to schedule database changes to match application change-control would not be workable. That is why /etc cannot be mounted read-only and still have /usr secured as read-only. This brings us back to a requirement that / and /usr be physically separate filesystems. [snip] > > I have about 6 or 7 backup jobs that run during the night and > > parse /etc/mtab to see if they need to place a copy of the backup > > onto an external medium. These examine the mount options and don't > > understand the non-standard options offered by Linux > > in /proc/mounts. > > Really? You cannot grep -v those options to another file and make the > jobs read this other file? I would use gawk rather than grep. But since I have code that already works, why should I need to develop a new script? > In my experience that sounds like a problem with the jobs. They work currently. Moreover, my rootfs is not read-only. It is not desirable to have the rootfs mounted read-only because of this problem and the other problems it causes. But for production systems it is desirable for /usr to be mounted read-only and only made writeable during a change-control window. [snip] > > They already don't do that. > > Well, then you already know what to do. Indeed I do. -- Regards, Dave [RLU #314465] *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* dwn...@ntlworld.com (David W Noon) *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
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