silver@csu-cs.UUCP (06/09/83)
/etc/mnttab (the mount table) is a mere shadow of the "true" internal
table kept by the kernel. Mnttab is manipulated by the mount, umount,
and setmnt commands. It can and often does contain "junk" entries
(devices not truly mounted), either for a good reason or because of
failure to clean up after a system crash or physical removal of a
volume. The only "good reason" I know of is the use of setmnt in
/etc/rc to put the root volume in the table, where it can be found by df
and other commands. I have two questions:
1: Are there any other good reasons for the tables to be separate, or
is this YAHK (yet another historical kludge)?
2: We're considering a kernel mod so you can either read the internal
table directly (via a new intrinsic) or have accesses to /etc/mnttab
magically reference the internal table, which would always contain
the root volume as the first entry. Writes to the table would
appear to succeed but change nothing (which makes setmnt obsolete).
Do you see any difficulties with these approaches, or the general
idea of merging tables?
Please mail me comments, and I'll summarize if there's enough interest.
Thanks!
Alan Silverstein, Hewlett-Packard Fort Collins Systems Division, Colorado
ucbvax!hplabs!hpfcld!ajs, 303-226-3800 x3053, N 40 31'31" W 105 00'43"