On Mon, 04 Jan 2010 20:13:56 +0100, Nicolas Williams <Nicolas.Williams at sun.com> wrote:
> On Tue, Dec 29, 2009 at 09:32:51AM -0800, Frank Batschulat wrote: >> Hey Sean, reading thru >> >> http://hub.opensolaris.org/bin/download/Community+Group+smf/smf_design_docs/emidesign.html >> >> <snip> >> 2.2. New manifest location >> >> Early manifest import will look in /etc/svc/manifest for manifests. This is >> a new storage location for manifests, and it is chosen to be on the root >> file system. Thus, it will be available as soon as root is mounted. >> Similarly, /etc/svc/profile is a new location for profiles. Services that >> need to take advantage of early manifest import must place their manifests >> in /etc/svc/manifest. >> <snip end> >> >> wasn't one of the inital goals of SMF in the past days to deliver the >> foundation to >> eventually enable a R/O root file system by moving volatile content and >> configuration >> information/files out of /etc ? >> >> (eg. look at the past eval comments wrt. SMF in bug: >> 4687824 RFE: support for read-only remount of / at boot time) >> >> so after all those years we've eventually giving up on that idea ? > > Read-only / does not imply "can't ever write to /". Otherwise upgrades > and installs of additional pkgs couldn't be done. What ro / does imply > is that you'd have to either remount -o rw before doing an upgrade/ > install, or, more likely (and as IPS does, for upgrades), write to a > clone BE and then reboot into the new BE. There's nothing wrong with > delivering software into /, nor with delivering service manifests into > /. quite Nico. I was just curious, years ago the apparent direction for R/O root was to essentially minimize roots volatile content so I was curious how we do now with putting more and more volatile content into root these days. indeed as you mention it'll work the way you describe, however for long running systems with an assumed R/O root, the desire to have volatile content out of root and thus variable without having the need to remount root R/W and again R/O after the change also has some attraction. afterall, not all changes to volatile content in /etc (or in this case, SMF manifests) happen during upgrade/install of add. packages but also due to random daily system administration. if we assume a R/O root, that'd require a remount R/W, remount R/O cycle of root. cheers frankB
