Excerpts from transarc.external.info-afs: 19-Jul-94 Re: Home directory
layouts... John [EMAIL PROTECTED] (1270)
> > > /afs/ir/users/[a-z]/[a-z]/$USER
> > This is the scheme we use at the umich.edu cell. We currently have
> > 10,000 home directories (we expect to double this over the next 12
> > months). The users/s/a directory has 130 entries in it, so the scaling
> > isn't bad for these common letters.
> We considered this scheme and (as is obvious from my previous post)
> rejected it. The data I have in front of me is for 18,990 users.
> Of the 962 (26*37) possible first two letters we allow in usernames,
> 655 are in use. The top 20 are:
Speaking from my experience, I really like the UM scheme. It's
immediately obvious to anyone where someone else's home directory is,
so they can go looking in /afs/ir/users/j/o/... I'd never guess what
your UID is, and my shell on my workstation here is probably never going
to do the right thing with "ls ~[EMAIL PROTECTED]". Why don't you just
add a level: /afs/ir/users/[a-z]/[a-z]/[a-z][0-9]/$USER (ie,
/afs/ir/users/j/o/h/john)
Or... make it a "real" trie, and go for broke: ~john ==
/afs/ir/users/j/o/h/n/
Of course, that doesn't work if you have names which are prefixes of
other names, so you're back to /afs/ir/users/j/o/h/n/john/.
If you do go for broke this way, the number of entries in any directory
will never be more than the number of used name characters plus one.
The hard upper bound on directory size will be 253, maybe lower.
Practically speaking, you will probably never have any more than 63
([a-zA-Z0-9]+prefix_terminator).
I'd like to explore a little bit why you think that more than 31 entries
in a directory is a problem. Since that may not be of general interest
to the list, why don't you send me email?
