The index card in the library for "War and Peace" takes a lot less space that the book itself, and so it is when you ask Linux or Unix "how much space is taken in this directory" ... you'll be told how big each of the files are, and how big
the index table for each subrirectory is. Here's an example from today's course, one of our training machines:
[trainee@easterton ~]$ ls -l
total 1224
drwxrwxr-x 4 trainee apache 4096 May 18 11:52 build
drwxrwxr-x 2 trainee apache 4096 Jun 4 11:56 dbn
drwxr-xr-x 2 trainee apache 4096 Jun 12 14:21 Desktop
-rwxr-xr-x 1 trainee apache 55 May 26 11:20 ls
drwxr-xr-x 3 trainee apache 4096 May 26 12:09 ppl
drwxr-x--- 2 trainee apache 4096 Jun 12 14:22 richard
-rw-r----- 1 trainee apache 81920 Jun 12 14:22 richard.tar
drwxr-x--- 3 trainee apache 4096 Jun 4 16:29 tombuild
-rw-r--r-- 1 trainee apache 22186 May 21 19:55 transwilts2009.odt
-rw-r--r-- 1 trainee apache 785849 May 21 19:55 transwilts_2009.pdf
-rw-r--r-- 1 trainee apache 313556 May 21 19:57 transwilts2009.pdf
drwxrwxr-x 4 trainee apache 4096 May 18 11:22 website
So that's telling me that the total size is 1224 Kbytes (just over 1 Mbyte) with most of the space in the file transwilts_2009.pdf. And there are 7 directories that are 4096 bytes each ...
Yes, but that's the directory entry size. Let's dig deeper:
[trainee@easterton ~]$ du -sk *
211020 build
243080 dbn
12 Desktop
4 ls
60348 ppl
152 richard
84 richard.tar
60352 tombuild
24 transwilts2009.odt
772 transwilts_2009.pdf
312 transwilts2009.pdf
461424 website
Once again, you see that the transwilts_2009.pdf file is 772k ... but the grand total has rocketed from just over 1 Mbyte to 461 Mbytes ... because we're now looking within each directory. They're not 4096 bytes each - that's just the index card. The website directory (as an example) is 461 Mbytes alone.
Courses -
Linux Admin Introduction and
LAMP deployment for folks who have to look after we servers.
(written 2009-07-20, updated 2009-07-22)
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
A162 - Web Application Deployment - Backups and File System Management [153] Linux - where to put swap space - (2004-12-16)
[334] Symbolic links and hard links - (2005-06-02)
[554] What backup is adequate? - (2006-01-04)
[593] Finding where the disc space has gone - (2006-02-06)
[703] Copying files and preserving ownership - (2006-04-28)
[735] Boys will be boys, saved by Ubuntu - (2006-05-27)
[754] tar, jar, war, ear, sar files - (2006-06-10)
[1013] Copy multiple files - confusing error message from cp - (2006-12-30)
[1023] Finding public writeable things on your linux file system - (2007-01-06)
[1288] Linux run states, shell special commands, and directory structures - (2007-08-03)
[1439] Linux / Unix - layout of operating system files - (2007-11-20)
[1648] The tourists guide to Linux - (2008-05-20)
[1765] Dialects of English and Unix - (2008-08-21)
[1801] Will your backups work if you have to restore them? - (2008-09-18)
[1893] Some Linux and Unix tips - (2008-11-18)
[4056] An overpractical test of our backup strategy! - (2013-03-30)
[4063] Backups by crossover between network centres - setting up automatic scp transfers - (2013-04-13)
[4115] More or less back - what happened to our server the other day - (2013-06-14)
[4390] Checking MySQL database backups have worked (not failed) - (2015-01-10)
[4400] Commenting out an echo killed my bash backup script - (2015-01-19)
[4405] Backup procedures - via backup server - (2015-01-24)
[4481] Extracting data from backups to restore selected rows from MySQL tables - (2015-05-01)
A101 - Web Application Deployment - Linux -An Introduction For Users [73] vi - full circle - (2004-10-04)
[74] pushd and popd - (2004-10-05)
[152] Aladdin, or careful what you wish. - (2004-12-15)
[249] An easy way out - (2005-03-17)
[430] Linux commands - some basics - (2005-08-31)
[431] File permissions of Linux and Unix systems - (2005-08-31)
[659] Web Application Components - (2006-03-28)
[679] More or less on the edge of the page - (2006-04-11)
[710] Linux training Glasgow, Python programming course Dundee - (2006-05-05)
[711] THE home directory or MY home directory - (2006-05-06)
[749] Cottage industry or production line data handling methods - (2006-06-07)
[984] Cardinal numbers and magic numbers - (2006-12-14)
[1012] Moving files between Windows / DOS and Linux / Unix - (2006-12-30)
[1068] ls -l report, Linux / Unix - types and permssions - (2007-02-06)
[1259] Where am I and how did I get here? - (2007-07-05)
[1287] Work and play at Well House Manor - Football and Shell Shortcuts - (2007-08-02)
[1366] awk - a powerful data extraction and manipulation tool - (2007-09-25)
[1408] Wireless hotel tips - FTP and Skype connections failing - (2007-10-26)
[1438] Copy and paste / cut and paste and other vi techniques - (2007-11-20)
[1527] Selecting file names in a shell - one word or another - (2008-02-02)
[1651] ls command - favourite options - (2008-05-23)
[1764] Yank and Push - copy and move in vi - (2008-08-21)
[1803] FTP passive mode - a sometimes cure for upload hangs - (2008-09-20)
[1897] Keeping on an even keel - (2008-11-21)
[1902] sstrwxrwxrwx - Unix and Linux file permissions - (2008-11-23)
[1904] Ruby, Perl, Linux, MySQL - some training notes - (2008-11-23)
[2201] Running straight from the jar, but not from a tar - (2009-05-26)
[2203] Always use su with minus. And where do programs come from? - (2009-05-27)
[2300] What does x on a linux directory mean? - (2009-07-21)
[2479] Accidentally typed ci rather than vi? - (2009-10-27)
[2494] Making Linux Politically correct - (2009-11-06)
[2636] Linux - useful tips including history and file name completion - (2010-02-15)
[2831] Recording (a macro) in vi - (2010-06-27)
[3179] Oops - I typed ci not vi, and have lost my file ... - (2011-02-21)
[3256] Displaying a directory or file system tree - Linux - (2011-04-22)
[3791] The Kernel, Shells and Daemons. Greek Gods in computing - (2012-07-01)
[3819] Packing a tar, jar or war file - best practise - (2012-07-26)
Some other Articles
Turning potential customers awaySee us at the West Wilts ShowMistaken identity?How much space does my directory take - LinuxMelksham Carnival Parade - the peopleStanding on the corner, Melksham CarnivalVariable scope - what is it, and how does it Ruby?The dog is not in troubleCan you learn to program in 4 days?