haynes@ucscc.ucsc.edu (Jim Haynes) (01/26/91)
The manuals say that the system when booting fires up /usr/etc/init. In my younger days a system came up with the root filesystem mounted but without /usr mounted. I'm not sure I like the new arrangement; I'm working with some configurations where /usr is just a bunch of symlinks to other places. What is the copy of init in /sbin for? Do I have to have /usr mounted at boot time? haynes@ucscc.ucsc.edu haynes@ucscc.bitnet
guy@uunet.uu.net (Guy Harris) (02/01/91)
>The manuals say that the system when booting fires up /usr/etc/init. The manuals lie. "/sbin/init" is what's fired up. (Well, actually, the kernel searches several directories, but "/sbin" is the first one it searches....) The manual probably said "/etc/init" prior to SunOS 4.0, and got updated to reflect the fact that programs in "/etc" moved to "/usr/etc". >In my younger days a system came up with the root filesystem mounted but >without /usr mounted. Well, when the system *first* comes up, only root is mounted, but it mounts "/usr" soon after that. > What is the copy of init in /sbin for? See above. > Do I have to have /usr mounted at boot time? See above. It has to get mounted fairly early in the boot sequence, because there's not a boatload of code on the root file system, by default; the executables and shared libraries are largely on the "/usr" file system.
jms@tardis.tymnet.com (Joe Smith) (02/02/91)
In article <1490@brchh104.bnr.ca> haynes@ucscc.ucsc.edu (Jim Haynes) writes: >The manuals say that the system when booting fires up /usr/etc/init. In >my younger days a system came up with the root filesystem mounted but >without /usr mounted. I'm not sure I like the new arrangement; I'm >working with some configurations where /usr is just a bunch of symlinks to >other places. What is the copy of init in /sbin for? Do I have to have >/usr mounted at boot time? haynes@ucscc.ucsc.edu haynes@ucscc.bitnet You can find some of the information you seek by doing the following: 1) ps ax | head 2) strings /sbin/init | more 3) grep mount /etc/rc.boot When a diskless workstation boots up, only the root directory and the swap space are defined. The executables in /sbin are the minimum required to mount /usr over NFS. They are: 1) /sbin/init - started automatically by vmunix 2) /sbin/sh - used to interpret /etc/rc.boot 3) /sbin/hostname - defines primary host name 4) /sbin/ifconfig - sets up IP address for the ethernet interface 5) /sbin/intr (new with 4.1) - allows ^C to abort mount 6) /sbin/mount - mounts /usr, either over NFS or as a local partition The above also applies to a diskfull Sun system. The manuals you refer to are wrong. Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms PO Box 49019, MS-C51 | BIX: smithjoe | CA license plate: "POPJ P," (PDP-10) San Jose, CA 95161-9019 | humorous dislaimer: "My Amiga 3000 speaks for me."