Todd Denniston wrote:
Ed Greshko wrote, On 03/31/2008 10:57 PM:
charles f. zeitler wrote:
--- Ed Greshko <Ed.Greshko@xxxxxxxxxxx> wrote:
charles f. zeitler wrote:
i've been pruning my "downloads" disk,
rather drastically, and not making a dent.
today some more, less drastic but still
hefty, same result.
revisited du- checked it twice - three
times- yup, it reports one directory at
800+ gb- on a 400gb disk!
fsck (forced) failed to report any problems,
there don't seem to be any symlinks,
and the sub-direcory sizes are sane...
any ideas welcome, and appreciated.
Instead of telling people what you are seeing it would be better to
show the actual commands and output.
good point.
[fedora_8@Nyarlethotep ~]$ df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdb1 384578164 330445976 34596748 91%
/home/fedora_8/torrents_isos
/dev/sdb1 is the drive under discussion.
[fedora_8@Nyarlethotep ~]$ du -sb t*s/*
34256010522 torrents_isos/backup
883393808812 torrents_isos/data
58352749159 torrents_isos/finished
<snip>
somethings wrong with t*s/data ....
OK.... I believe I know what the problem is. The torrents_isos/porn
directory makes things seem larger than what they really are....
No, just kidding.....
I believe you may have a bunch of non-completed torrent downloads.
When you start a torrent download the client will reserve the space
and it will be reflected in the output of "du" but *not* in the output
of "df". Thus with "du" you can have a situation where it "thinks"
more disk space is being used than it actually is. FWIW, this is normal.
I think Ed is on the right track, but the strange thing is the reserve
would happen sparse...
cd /dev/shm/
mkdir normal sparse
dd if=/dev/zero of=normal/bunchozeros bs=1M count=20
cp --sparse=always normal/bunchozeros sparse/
ls -l normal/* sparse/*
-rw-r--r-- 1 root root 20971520 2008-04-01 09:28 normal/bunchozeros
-rw-r--r-- 1 root root 20971520 2008-04-01 09:30 sparse/bunchozeros
du -sb *
20971580 normal
20971580 sparse
du -s *
20504 normal
0 sparse
df -h .
Filesystem Size Used Avail Use% Mounted on
tmpfs 1014M 21M 994M 2% /dev/shm
OK!!!
df is showing how much disk is used/free based on inodes and filesizes
(you can run out of space if you have no inodes left).
Incorrect. df reads out the free blocks on the filesytem, file sizes and inodes
don't have anything to do with it.
The only way for du to differ from df (without a system issue) is for there to
be files that have been deleted but are still being accessed, see below for
things caused by system issues.
And if you run out of inodes it can show a lot of space being left free even
though you don't have any inodes to be able to use it.
du -s, du -sm show how much disk space is REALLY used on disk by the files.
du -b implies --apparent-size
du --apparent-size "print apparent sizes, rather than disk usage"
All correct.
I have seen corrupt directory entries that indicate that blocks are being used
(for a given file) that are not actually being used (or possibly don't even
exist at all) cause du to return wrong results, one would need to look through
the files in the funny directory and see if any of the sizes look wrong, given
that they are certain kinds of files there is a certain range that should be
valid, and an entry having something way outside of that range should be a hint
that that directory entry is corrupted. Often fsck will be unable to remove
the entries, I have had to use filesystem debuggers to remove this type of file
before, but even with those tools it is often difficult. I would expect one or
more files to be of a obviously wrong size.
If the systems crashes at exactly the wrong time, you can get some corrupted
entries.
Roger
