Tag: linux

Oracle Linux 6.5 released

Posted on by Osama Mustafa in Operating system
Oracle Announced the release of Oracle Linux 6.5, The Latest Version Of Oracle Linux, It’s only Other Operating System Because this version Contain Some New Features :

  • Unbreakable Enterprise Kernel Release 3
  • Support DTrace.
  • Delivering Better Performance, scalability   and reliability For Companies.
  • New File System : btrfs enable administrators to implement an efficient incremental backup mechanism using file system snapshots.
And More Features.
You Can download Oracle Linux 6.5 Here
It will be Available soon On Oracle Software Delivery Here

rdesktop: A Remote Desktop Protocol Client

Posted on by Osama Mustafa in Others
rdesktop is an open source client for Windows Remote Desktop Services, capable of natively speaking Remote Desktop Protocol (RDP) in order to present the user’s Windows desktop. rdesktop is known to work with Windows versions such as NT 4 Terminal Server, 2000, XP, 2003, 2003 R2, Vista, 2008, 7, and 2008 R2. Click Here.

You can install the package using yum like the below :

# rpm -qa rdesktop

Regarding to website to connect Windows from linux you need to use -u which indicate for username follows with hostname to be like this

# rdesktop -u Administrator osama

Osama : hostname
Administrator : Username

Useful !!!

Thank you
Osama mustafa

Linux Command For DBA

Posted on by Osama Mustafa in Operating system
Enable SSH in Linux: –
#chkconfig –list sshd
#chkconfig –levels 2345 sshd on

to find a file in a directory:-
$ find (directory_path) -name (file_name)

to find a value in a vi editor:-
in vi editor [esc] & :/(find_value)

to delete a value in a vi editor:-
in vi editor [esc] & :%s /delete_value

to delete contents in a file:-
in vi editor [esc] & :/%d

to replace a value in a vi editor:-
in vi editor [esc] & :%s /search_value/replace_value

to see the size of a file (or) directory:-
$du -csh (file or directory name)

to count the files & directories in a directory:-
$ls -l |wc -l

to count the files in a directory:-
$find . -type f |wc -l

to count the directries in a directory:-
$find . -type d |wc -l

to see the file-system in linux:-
$file /sbin/init
(or)
$getconf LONG_BIT

How to mount Windows shared folder in Linux: –
$mount.cifs //IPAddrss/share_folder_name/ /mnt -o user=username

Thank you 
Osama Mustafa

ORA-12516: TNS:listener could not find available handler

Posted on by Osama Mustafa in Database
after the increasing the Number processes in the Oracle database, it solved the problem.

But Before this , i am gonna show you some steps to check the process via OS and Database LETS BEGIN :

  • check if the number of connections reaches the database’s  process parameter using following Unix command: 
ps -ef | grep oracleSID | grep -v grep | wc -l
or
ps aux | grep oracleSID | grep -v grep | wc -l
  •  check if the number of connections reaches the database’s  process parameter using following Database Command :
SQL> show parameter processes

NAME                TYPE        VALUE
------------------ ----------- -------
processes           integer     150

SQL> select count(*) from v$process;

  COUNT(*)
----------
       149
SQL> show parameter sessions

NAME                TYPE        VALUE
------------------ ----------- -------
Session              integer     150

SQL> select count(*) from v$session;

  COUNT(*)
----------
       149

Now We need To Increase the Both Parameter By :

SQL> alter system set processes=300 scope=spfile;

System altered.
 
SQL> alter system set Session=300 scope=spfile;

System altered.

If this Solution Not Work For you , Try this One :

SQL> alter system set local_listener=
“(ADDRESS=(PROTOCOL=tcp)(HOST=10.122.28.12)(PORT=1521))” sid=’ORCL1′;

System altered.

SQL> show parameter local

NAME                                 TYPE        VALUE
———————————— ———– ——————————
local_listener                       string      (ADDRESS=(PROTOCOL=tcp)(HOST=1
                                                 0.122.28.12)(PORT=1521))

Thank you 

Osama Mustafa

Backup an entire hard disk using dd command

Posted on by Osama Mustafa in Operating system
The ‘ dd ‘ command is one of the original Unix utilities and should be in everyone’s tool box. It can strip headers, extract parts of binary files and write into the middle of floppy disks; it is used by the Linux kernel Makefiles to make boot images. It can be used to copy and convert magnetic tape formats, convert between ASCII and EBCDIC, swap bytes, and force to upper and lowercase. 

# dd –help

full hard disk copy

dd if=/dev/hdx of=/dev/hdy
dd if=/dev/hdx of=/path/to/image
dd if=/dev/hdx | gzip > /path/to/image.gz

Hdx could be hda, hdb etc. In the second example gzip is used to compress the image if it is really just a backup.  



Restore Backup of hard disk copy

dd if=/path/to/image of=/dev/hdx

gzip -dc /path/to/image.gz | dd of=/dev/hdx  




MBR backup

In order to backup only the first few bytes containing the MBR and the partition table you can use dd as well.

dd if=/dev/hdx of=/path/to/image count=1 bs=512 



MBR restore

dd if=/path/to/image of=/dev/hdx

Add “count=1 bs=446” to exclude the partition table from being written to disk. You can manually restore the table.

 “All This Information was taken from the other site , just for information to take hard-disk backup , it will be useful to use it with Oracle ”

thank you 
Osama mustafa  
  

Change Oracle Enterprise Manager 10g Password

Posted on by Osama Mustafa in Application
How to change the password of the Database User SYSMAN when the database is hosting a DB Control Repository. 

1.Stop the DB Control
On Unix
$ emctl stop dbconsole

On Windows
Open a Command Window and type
**> emctl stop dbconsole

2.Check that the DB Control is stopped
On Unix

$ emctl status dbconsole

On Windows
Open a DOS Command Window and type
**> emctl status dbconsole


3.Connect to the database as a user with DBA privilege with SQL*Plus and execute:

SQL> alter user sysman identified by ;

4.Check the new password 

SQL> connect sysman/[@database_alias]
 

5.Go to $ORACLE_HOME/host_sid/sysman/config do the following :

    1. Save the file emoms.properties to emoms.properties.orig
    2. Edit the file emoms.properties
      1. Search for the line beginning with:
        oracle.sysman.eml.mntr.emdRepPwd=
        Replace the encrypted value by the new password value
        Example:
        oracle.sysman.eml.mntr.emdRepPwd=rainbow
      2. Search for the line:
        oracle.sysman.eml.mntr.emdRepPwdEncrypted=TRUE
        Replace TRUE by FALSE

6.Restart the DB Control
On Unix

$ emctl start dbconsole
 
Open a DOS Command Window and type
**> emctl start dbconsole
 
 
7.Check that the password has been encrypted
  1. Edit the file $ORACLE_HOME/host_sid/sysman/config/emoms.properties
    1. Search for the line beginning with:
      oracle.sysman.eml.mntr.emdRepPwd=
      Check that the password is encrypted
    2. Search for the line beginning with:
      oracle.sysman.eml.mntr.emdRepPwdEncrypted=
      Check that the value is TRUE

I Publish the same lesson but on 11g .

  Thank you 
Osama mustafa