Article View: mod.computers.vax
Article #3851Re: Computing Disk Usage
From: LEICHTER-JERRY
Date: Sat, 21 Mar 1987 12:02
Date: Sat, 21 Mar 1987 12:02
58 lines
3576 bytes
3576 bytes
(Hi, Jack!)
...
Using several ways to compute disk usage, these are the figures I came up
with for a particular user (note: the files for this user are pretty
static - the user did not login while I was obtaining these figures):
944 blocks from the DISKQUOTA utility
860 blocks allocated - from DIRECTORY/SIZE=ALL/BY_OWNER=[?]
disk:[000000...]
579 blocks used - from DIRECTORY/SIZE=ALL/BY_OWNER=[?]
disk:[000000...]
668 blocks as reported by an accounting system we are testing
The documentation for the accounting system we are testing says it reads
the INDEXF.SYS file and gets the number of blocks for each file on that
disk owned by that user.
Questions:
1. Why the difference between the DISKQUOTA utility and the number of
blocks allocated (as shown by the DIRECTORY command)?
I called the DEC 800 number in Colorado and asked them this question.
They said the DISKQUOTA utility doesn't include lost files or the file
header blocks for each file owned by that user. The DIRECTORY command
includes the file header blocks, but not lost files. I did an
ANAL/DISK on the disk, and it didn't show any lost files.
Each file costs at least one header block, sometimes more (for large or very
fragmented files or files with large ACL's, for example). The numbers you've
got - 944 blocks shown by DISKQUOTA, 860 by DIRECTORY - could be accounted for
by having 84 files with 1-block headers; this gives an average file size (used
blocks) of 6 blocks, which isn't unreasonable for some kinds of users.
2. Why would there be a difference in the information in the INDEXF.SYS
file and what DISKQUOTA and DIRECTORY show? (I am assuming the
accounting system we are testing is correct - maybe a bad assumption
though).
Disk quota entries have been known to be wrong. Did you do a REBUILD? After
a REBUILD, what DISKQUOTA shows should be exactly what's in the INDEXF file.
If they still disagree, I'd assume errors in your accounting system. A likely
place to look: There are oodles of caches for things, especially in a clus-
ter. Just reading INDEXF.SYS may not give you up-to-date values. (The caches
are organized to favor reliability over accuracy, so blocks may show up as
allocated in INDEXF.SYS when they really aren't; but the other way around is
unlikely.)
For those of you that charge users for using disk space on your machine,
on what figures do you base your disk space usage? With the accounting
system we have been using for some time (not the one we are testing), we
have been using the figures from the DISKQUOTA utility.
We use the PACS software, which I believe uses DISKQUOTA's figures.
-- Jerry
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ames!ucbcad!ucbvax!YALE.ARPA!LEICHTER-JERRY From: LEICHTER-JERRY@YALE.ARPA.UUCP Newsgroups: mod.computers.vax Subject: Re: Computing Disk Usage Message-ID: <8703211201.AA13295@ucbvax.Berkeley.EDU> Date: Sat, 21-Mar-87 07:02:18 EST Article-I.D.: ucbvax.8703211201.AA13295 Posted: Sat Mar 21 07:02:18 1987 Date-Received: Sun, 22-Mar-87 14:59:18 EST Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: <LEICHTER-JERRY@YALE.ARPA> Distribution: world Organization: The ARPA Internet Lines: 58 Approved: info-vax@sri-kl.arpa