04-08-2014
First: you should put your database not in "/usr" - never! "/var" is only slightly better, but still not right. Create a directory "/opt", then create a filesystem "/opt/mydatabase" (or whatever - name is up to you), mount this filesystem and put your database there. The reason is that every directory in UNIX has its fixed contents and "/usr" is for the operation system. Search for "file system hierarchy standard" on the net and you will find a document explaining all this in detail. FHS is not a standard, but a very good guideline.
Second: a database is a collection of files, managed by some software. The files (what the OS reports as size) are of fixed size and are preallocated (mostly for reasons of speed). If this preallocated space is filled with something or not does not make any difference for the OS. PhpMyAdmin is a tool which queries the database software and this will tell you how much content is really stored within this space. But if you delete (or add) content this will change nothing for the size of the preallocated files the database uses. This is why the OS and PhpMyAdmin report different sizes for the database. To reduce the space the OS sees you need to shrink the "tablespaces" (i hope it is called this in MySQL too - this is the name in Oracle) to release some of the preallocated space.
I hope this helps.
bakunin
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
question abt symbolic link ...
i'm doing the following ...
ln -s x.sh ./scripts/y.sh
and
cat ./scripts/y.sh
it is giving following error
cat: cannot open y.sh
Any reason u an think of ?
But it is working fine when i goto scripts directory and cretae the symbolic link.
... (1 Reply)
Discussion started by: bhargav
1 Replies
2. UNIX for Dummies Questions & Answers
hello folks
how y'all doin
well i have some questions about symbolic link and hard link
hope some one answer me
i open terminal and join as root
and i wrote ln -s blah blah
then i wrote ls
i see red file called blah blah
but didn't understand what is this can some one explain and... (2 Replies)
Discussion started by: detective linux
2 Replies
3. Shell Programming and Scripting
Hi,
i am trying to create sym links on sles 11 , but it seems i am doing something wrong.
oracle@tests:/u01/app/oracle/oradata/ACIS> pwd
/u01/app/oracle/oradata/ACIS
oracle@tests:/u01/app/oracle/oradata/ACIS> ln -s /db/ACIS/dbase/dbf/ /u01/app/oracle/oradata/ACIS/... (2 Replies)
Discussion started by: tonijel
2 Replies
4. Shell Programming and Scripting
Hello All,
This may be a silly question to some but I am really stuck.
Is there a way to reverse the following;
sudo rm /bin/sh
sudo ln -s /bin/bash /bin/sh
It was part of a driver compile/installation procedure by Digi for Ubuntu stating that dash isn't supported and a symbolic link... (2 Replies)
Discussion started by: LAVco
2 Replies
5. Shell Programming and Scripting
CAN I download an html file via wget and pass it to mysql and update a database field? (8 Replies)
Discussion started by: mapasainfo
8 Replies
6. Shell Programming and Scripting
Hi all,
Can anyone please confirm if the command below is the only way that I can get what the symbolic link is set to?
mnlxd110(oracle)/db/posd2/dba$: ls -l | grep "^l"
lrwxrwxrwx 1 oracle dba 28 Aug 9 2011 bdump -> diag/rdbms/posp1/posp1/trace
mnlxd110(oracle)/db/posd2/dba$:... (7 Replies)
Discussion started by: newbie_01
7 Replies
7. UNIX for Dummies Questions & Answers
Hi everybody,
I read about treads realted to this issue but they did not resovle issue given below.
Please help me resolve issue given below
I have html file under /srv/www/htdocs/actual_folder
ls actual_folder/
test.html
and following link works... (0 Replies)
Discussion started by: newbielgn
0 Replies
8. UNIX for Dummies Questions & Answers
Hi, trying to understand more about symblic link, when I compiled a program called "match" in one folder ~/downloadsoftware/I want this program to be accessible like a system command by putting a symbolic link in /usr/bin/ Not by setting the $PATH method in .bashrc at this time.
What I did is:... (4 Replies)
Discussion started by: yifangt
4 Replies
9. Red Hat
this is my current code,
# ln -s /lib64/
# ls -lrth
total 80K
-rw-r--r--. 1 root root 12K Jul 6 2012 post-install
-rw-r--r--. 1 root root 552 Jul 6 2012 post-install.log
-rw-------. 1 root root 1.5K Aug 21 2012 anaconda-ks.cfg
drwxr-xr-x. 2 root root 4.0K Aug 21 2012 Videos... (3 Replies)
Discussion started by: jediwannabe
3 Replies
10. UNIX for Advanced & Expert Users
Any help appreciated just logging in to this server which is a front end for Rocks Cluster 6.1.1. Getting the below errors:
ldconfig
ldconfig: /usr/lib/libX11.so.6 is not a symbolic link
ldconfig: /usr/lib/libjpeg.so.62 is not a symbolic link
ldconfig: /usr/lib/libpng12.so.0 is not a symbolic... (3 Replies)
Discussion started by: RobbieTheK
3 Replies
dbm(3C) dbm(3C)
NAME
dbminit, fetch, store, delete, firstkey, nextkey, dbmclose - database subroutines
SYNOPSIS
DESCRIPTION
These functions maintain key/content pairs in a database. They handle very large (a billion blocks (block = 1024 bytes)) databases and can
locate a keyed item in one or two file system accesses.
key and content parameters are described by the type. A specifies a string of dsize bytes pointed to by dptr. Arbitrary binary data, as
well as normal ASCII strings, are allowed. The database is stored in two files. One file is a directory containing a bit map of keys and
has as its suffix. The second file contains all data and has as its suffix.
Before a database can be accessed, it must be opened by At the time of this call, the files and must exist. (An empty database is created
by creating zero-length and files.)
Once open, data stored under a key is accessed by and data is placed under a key by Storing data on an existing key replaces the existing
data. A key (and its associated contents) is deleted by A linear pass through all keys in a database can be made, in (apparently) random
order by using and returns the first key in the database. With any key, returns the next key in the database. The following code can be
used to traverse the database:
A database can be closed by calling A currently open database must be closed before opening a new one.
DIAGNOSTICS
All functions that return an indicate errors with negative values and success with zero. Functions that return a indicate errors with a
null dptr.
WARNINGS
The dbm functions provided in this library should not be confused in any way with those of a general-purpose database management system
such as ALLBASE/HP-UX SQL. These functions provide for multiple search keys per entry, they protect against multi-user access (in other
words they do not lock records or files), and they provide the many other useful data base functions that are found in more robust database
management systems. Creating and updating databases by use of these functions is relatively slow because of data copies that occur upon
hash collisions. These functions for applications requiring fast lookup of relatively static information that is to be indexed by a single
key.
The file will contain holes so that its apparent size is about four times its actual content. Some older UNIX systems create real file
blocks for these holes when touched. These files cannot be copied by normal means (such as cp(1), cat(1), tar(1), or ar(1)) without expan-
sion.
dptr pointers returned by these subroutines point into static storage that is changed by subsequent calls.
The sum of the sizes of a key/content pair must not exceed the internal block size (currently 1024 bytes). Moreover, all key/content pairs
that hash together must fit on a single block. returns an error if a disk block fills with inseparable data.
does not physically reclaim file space, although it does make it available for reuse.
The order of keys presented by and depends on a hashing function, not on anything interesting.
A or during a pass through the keys by and may yield unexpected results.
AUTHOR
dbm(3C) was developed by the University of California, Berkeley.
SEE ALSO
ndbm(3X).
dbm(3C)