Can't login as SYS user from SQL Developer - Oracle 11g

Problem:

Couldn't login as SYS user to Oracle 11g Database through SQL Developer.
But I could log in through SQLPLUS with the same username & password.
Tried several times through SQL developer(By selecting right options) but only SYS user seems to have this problem.

Solution:

1.Login the remote server and login as sys/123 as sysdba.(Or whatever your password)
2.Reset the password ( alter user sys identified by 123;)(With your prefered password)
3.Relogin the oracle as sys.

Now I could log in to the SQL developer through SYS user successfully.I know it's strange..but it worked!

Oracle SQL Developer: Can't edit in SQL Worksheet

Problem:

In SQL Worksheet you cant edit or use back space.
This may happen on newly installed Oracle SQL Developer.

Solution:

Go to  Tools | Preferences | Accelerators and press  Load Preset.
Then it'll  load the default preset.
Then try again to edit.

Virtual Box Error - VT-x features locked or unavailable in MSR.

Error:

Failed to open a session for the virtual machine

VT-x features locked or unavailable in MSR.
(VERR_VMX_MSR_LOCKED_OR_DISABLED)

The details are:

Result Code:
E_FAIL (0×80004005)
Component:
Console
Interface:
IConsole {1968b7d3-e3bf-4ceb-99e0-cb7c913317bb}



Solution:

You have to change the processor Number to get rid of this error.

So go to vitual-Box Machine–>setting–>system–>Processor–> change the CPU No. to 1.
Then restart the VM and it'll work.

Oracle SQL Developer Unable To Find Java Virtual Machine

The Oracle SQL developer is NOT supported on 64 bits JDK.

Your PC environment may be :

Database : Oracle 11g / OS Platform : Windows 7 Ultimate 64 bits / JDK : 1.6 .0_24, 64 bits

So it will give you an error when trying to open SQL Developer.

When you click on the Oracle SQL developer, it prompts you to give the JDK folder location. However, after you specified the correct JDK folder, it prompts you following error dialog box :

Unable to find Java Virtual Machine. To point to a location of a Java Virtual Machine....

Solution

To solve it, install a 32 bits / x86 JDK and update your SQL developer config file, so that it points to the 32 bits JDK.

Edit the “sqldeveloper.conf“, which can be found under {ORACLE_HOME}\sqldeveloper\sqldeveloper\bin\sqldeveloper.conf, make sure “SetJavaHome” is pointing to your 32 bits JDK.

How to list all users in Linux

To list only usernames type the following awk command.

awk -F':' '{ print $1}' /etc/passwd


Eg:

[root@jbsvr u01]#   awk -F':' '{ print $1}' /etc/passwd

root
bin
daemon
adm
lp
sync
shutdown
halt
mail
news
uucp
operator
games
gopher
ftp
nobody
rpm
dbus
nscd
vcsa
pcap
rpc
mailnull
smmsp
sshd
rpcuser
nfsnobody
haldaemon
avahi
apache
ntp
xfs
gdm
sabayon
jboss
jbtest
apacheds
avahi-autoipd
oprofile
exim
oracle
orafin
amandabackup

Create a Local Repository on RHEL 6.3 for Yum Installer

Step1: Mount the OS disk and copy the contents to a local path which will be the main repository path:

mkdir -p /linuxdvd/

cp -RH /mnt/dvd/* /linuxdvd/

Step2: Create new yum repository (e.g. rhel-local.repo)

Create the repo file

vi /etc/yum.repos.d/rhel-local.repo

Insert the below content to the file.Change the details according to your environment.

[rhel6.3-local]

name=RHEL 6.3 local repository

baseurl=file:///linuxdvd/

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

enabled=1

Convert FAT32 disk to NTFS in Windows

Issue below command in DOS prompt.

convert <Drive Letter>: /fs:ntfs

Eg:

C:\Documents and Settings\pubudu>convert l: /fs:ntfs

The type of the file system is FAT32.
Volume PUBUDU-SUPP created 8/3/2012 4:29 PM
Volume Serial Number is B0FB-D07D
Windows is verifying files and folders...
File and folder verification is complete.
Windows has checked the file system and found no problems.
   15,609,312 KB total disk space.
           32 KB in 4 hidden files.
        3,344 KB in 413 folders.
    3,453,464 KB in 2,611 files.
   12,152,464 KB are available.

        8,192 bytes in each allocation unit.
    1,951,164 total allocation units on disk.
    1,519,058 allocation units available on disk.

Determining disk space required for file system conversion...
Total disk space:              15624576 KB
Free space on volume:          12152464 KB
Space required for conversion:    85614 KB
Converting file system
Conversion complete

Change User Password in Linux

Steps to Change User Password in Linux

1.Login as the root user

2.Type the following command:
passwd oracle

3.Enter New password

4.Confirm the new password

5.Then open another terminal and login as Oracle with new password.

Eg:

login as: root
root@191.161.201.111's password:
Last login: Thu Mar  7 00:32:14 2013 from 191.161.201.111
[root@my ~]# passwd oracle
Changing password for user oracle.
New password:

How to configure Red Hat Enterprise Linux 6 to use with Xmanager

Use below steps to  configure Red Hat Enterprise Linux 6 to use with Xmanager

1. Open /etc/gdm/custom.conf and edit the security and xdmcp section like the followings:

[security]
DisallowTCP=false

[xdmcp]
Enable=true


3. Add UDP port 177 to the Allow list on firewall.

2. As an admin, do 'init 3' and then, 'init 5'

Network Connection not getting up in RHEL 6

After installing RHEL 6 you may not be able to get network connection up on booting the machine.
This is a reported bug in RHEL 6.

Follow below steps to solve the issue.

Edit  /etc/sysconfig/network-scripts/ifcfg-eth0  file, which is your default first NIC configuration file.



If you are using DHCP server:

Edit below file and change as given below

#vi /etc/sysconfig/network-scripts/ifcfg-eth0


ONBOOT="yes"
BOOTPROTO="dhcp"


Save & restart networking service,

#service network restart 



If you are providing manual IP:


Edit below file and change as given below

#vi /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
IPADDR=192.10.110.10
NETMASK=255.255.255.0
NETWORK=10.10.10.0
GATEWAY=192.9.110.253
ONBOOT=yes
BOOTPROTO=none
USERCTL=no


Save & restart networking service,

#service network restart