There a two quota limits, the soft limit and the hard limit. You can continue to increase your usage over the soft limit until you either reach the hard limit or the established time limit(usually a week). Once either of these events have occured all further attempts at file creation will fail with an error message. If you ever see the messages:
DISK LIMIT REACHED -- WRITE FAILED
FILE LIMIT REACHED -- CREATE FAILED
you have exceeded your hard limit.
% quota -v
Disk quotas for scot (uid 19072):
Filesystem usage quota limit timeleft files quota limit timeleft
/home/huron2
1668 9000 10000 0 0 0
%
If this command returns nothing you don't have a quota. The following table
explains each column.
The du (disk use) command recursively displays the amount of disk space (in blocks) used in each directory. The -s (summary) will display the total blocks used by each directory and the -a (all) option will list filenames.
% du -s * 654 tutorial %This will summarize the disk usage starting from your home directory.
If you exceed your quota limit you can use the tar and compress commands to reduce your disk usage. After you have compressed you files and you still need more disk quota speak with your system administrator.
find path_name_list [options]
Where path_name_list is one or more directories.
% find . -name Makefile -print /home/huron2/admin/scot/tutorial/Makefile %The . is a directory abbreviation for the current directory. The -name option specifies that only files with the given name should be found. The name option can include wildcard characters if they are quoted. There are many options to the find command, a few are listed in Table8.2.
% find . -name "core*" -size +3 -mtime +7 -exec rm -i {} \; -print
/home/huron2/admin/scot/core: ? (y/n) y
/home/huron2/admin/scot/core
%
Table8.2: Some Options to Find
--------------------------------------------------------------------
-name file Find files named file
-size n Find files that contain size...
n exactly n blocks (1 block = 512 bytes)
+n more than n blocks
-n less than n blocks
-mtime n Find files that were modified
n exactly n days ago
+n more than n days ago
-n less than n days ago
-exec cmd Execute command cmd on each file
-type type Find files that match the type
f ordinary file
d directory
b block device
c character device
p named pipe
--------------------------------------------------------------------
Actions can be taken when files are found by using the -exec option. The -exec
option uses the {} (left curly-brace right curly-brace) syntax to specify the current file that find has found. The exec command ends with the \; syntax. If we did not have the print option at the end we would not get a confirmation the file had been removed.
had been removed.
% tar -cvf tut.tar tutorial a tutorial/Makefile 1 blocks a tutorial/friends 1 blocks a tutorial/hello.cc 1 blocks a tutorial/postscript/mosaic.ps 638 blocks a tutorial/core symbolic link to /dev/null a tutorial/friends.pl 2 blocks % ls tut.tar tut.tar %Here we have created tut.tar as an archive of the files in our tutorial directory. The -c (create) option is used to create a new tape archive and write files. The -v (verbose) option display the names of archived files. The -f (file) option specifies that the next argument is the archive source or destination. If you exclude the -f option tar will use the default(usally /dev/rmt/0m). Let extract the tutorial files.
% tar -xvf tut.tar x tutorial/Makefile, 242 bytes, 1 tape blocks x tutorial/friends, 416 bytes, 1 tape blocks x tutorial/hello.cc, 70 bytes, 1 tape blocks x tutorial/postscript/mosaic.ps, 326291 bytes, 638 tape blocks x tutorial/core symbolic link to /dev/null x tutorial/friends.pl, 864 bytes, 2 tape blocks %The -x(extract) option will extract the files from the tape archive. Since we have the tut.tar file we can remove our tutorial directory. Before we extracted the contents of a tar file we could have use the -t (table) option to get a listing of the table of contents.
% compress -v tut.tar tut.tar: Compression: 78.19% -- replaced with tut.tar.Z % ls -l tut.tar.Z -rw-r--r-- 1 scot admin 79883 Mar 30 16:02 tut.tar.Z %The -v (verbose) option is used to list the amount of compression.
The uncompress command has the same syntax as compress.
% uncompress tut.tar.Z % ls -l tut.tar % ls -l tut.tar -rw-r--r-- 1 scot admin 337920 Mar 30 16:02 tut.tar %Recently some sites have been using a new compression program. The GNU zip and unzip programs are being used because they offer a more effective compression algorithm. The gzip (GNU zip) command will compress a file and the gunzip (GNU unzip) will decompress a file.
% gzip -v tut.tar tut.tar: 82.4% -- replaced with tut.tar.gz %Here we see a compression of 82% using gzip, whereas the compress program gave us 78%.