How do you find the symbolic links to files.

Root Boy Jim rbj at uunet.UU.NET
Wed Dec 19 14:34:36 AEST 1990


I agree that a system call to allocate a big chunk of disk would be nice.
Your example about a music program is well taken. It would also be nice
if truncate would deallocate space in the middle of a file.

The fact that that I termed it an environmental or administrative
problem doesn't mean that it's not a problem. One solution is
to just have lots of space. We stop batching news when our uucp
spool directory gets below 10M. Since articles are rarely that
big, we don't have a problem, even with alt.sex.pictures :-)

Why would you want to copy a core file? Just debug it in place, or symlink it.
And just how big can a core file be anyway? A few meg? Possibly 10?

If you are running big applications, you need lots of room, and then
somewhere between 10% to 20% extra. If you know exactly what you need,
then preallocation by writing nonzero data might be good.

OK, enuf speculation on what should be. Here's what is:

Don't ever count on holes being there, figure on having to store it all.
Exception: use experience, "Well, this database looks like 100M, but
is really a 17M DBM file".

Holes are not very well supported. Only lseek can create them,
and write never does. Someone has to decide when to look thru a
buffer and make a hole or write real data. Since it's not all
that hard to do, the few users who care must shoulder the burden.

Holes are fragile. If data is moved in any way, they are likely
to be filled. Archivers *should* preserve them, but may not.

If you care about making holey files, you will need a program
to recreate them. And you need space for both files for awhile.

Holes are not useful all that often. A database here and there
and/or image data or whatever. Programs use bss to store zeros.

If your application is heavily based on one of the above, perhaps
you would be wise to use a raw disk instead and manage space yourself.
-- 

	Root Boy Jim Cottrell <rbj at uunet.uu.net>
	Close the gap of the dark year in between



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