Are links as useful as they could b

wombat at ccvaxa.UUCP wombat at ccvaxa.UUCP
Mon Sep 29 11:14:00 AEST 1986


My pet peeve with links:

We do some of our development here within "boxes", which are miniature unix
filesystems reached via dressed-up chroot calls. The nice thing about them
is that you can have complete control over your development environment. The
problem is that for each box you set up on a different partition (and almost
all of them are on different partitions), you must also install copies of
stardard utilities, including most of /bin and /lib plus some of /usr/lib,
/usr/bin, and /usr/ucb plus emacs. These have to be real copies, because we
don't have nearly enough room on our root disks to put development projects
thus making hard links useless, and because symbolic links can't be followed
to a target outside of a box. And there goes half the disk space from your
box. (Idle speculation says it would be nice if symlinks could reach through
a chroot call, but since we also use boxes for security I don't think I
could convince other people we should do it.)

I disagree that "most uses of links are to connect things in the same
directory":

We have a project here that uses a stable, common source tree. The
developers working on it usually need to change only a few files, but we
want them to do it in their own copy of the tree so that they can test it
before checking it into the official tree. So they make a copy of the
official tree which starts off consisting entirely of directories and hard
links to (non-RCS *,v) files in the official tree. When a developer wants to
change a file, they first remove the linked version, then get a true copy
and edit away. Since the source directory is over 10,000 blocks this saves a
lot of disk space. (However, if you ever have to restore the partition from
full+incremental dumps you have a really nasty problem on your hands, as we
have already discovered.)

(You may have guessed from this that our greatest shortage around here is
disk space.  B-)

"Our first order of business will be to find a deranged alchemist, which
should not be very difficult. China," said Master Li, "is overstocked
with deranged alchemists."
Barry Hughart, *Bridge of Birds*		Wombat
					ihnp4!uiucdcs!ccvaxa!wombat



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