Cannot retrieve repository metadata (repomd.xml) for repository: c5-media

Description of the Problem

I have newly installed Centos 5 and when I was trying to run Add/Remove Software I got the following error:

Unable To Retrieve Software Info, Package Manager

Also I tried installing package using yum, but showing the following:

Error: Cannot retrieve repository metadata (repomd.xml) for repository: c5-media.
Please verify its path and try again

Solution of the Problem

su –
vi /etc/yum.repos.d/CentOS-Media.repo

find the string “enabled=1”  to “enabled=0”.

That’s it. Just re-run Package Manager.


Database Mail – test is OK, but jobs do not notify

  1. Run SQL Server Management Studio.

  2. In Object Explorer, expand the server.

  3. Right-click on the SQL Server Agent and then click its Properties.

  4. Click Alert System.

  5. Check Enable Mail Profile.

  6. In the Mail system list choose Database Mail.

  7. In the Mail profile list select a mail profile.

  8. Restart the SQL Server Agent

Good Luck!

ORA-01017: invalid username/password; logon denied(database link error)

When I was creating database link from Oracle 10g to 11g like that:

SQL> create database link mylink_name connect to myuser_name identified by mypassword using 'MYSID';

Database link created

got ORA-01017 error.


This may happen if in 11g database, there is enabled the following parameter:

SQL> show parameter sec_case_sensitive_logon;

NAME                                 TYPE        VALUE
----------------------------------- --------- ------------------------------
sec_case_sensitive_logon             boolean     TRUE



Recreate database link by the following way:

SQL> drop database link mylink_name;

Database link dropped

SQL> create database link mylink_name connect to "myuser_name" identified by "mypassword" using 'MYSID';

Database link created

To check it:

SQL> select * from dual@mylink_name;


Configuring SSH access for VirtualBox Host to Guest

I have installed VirtualBox with CentOS. I’ve decided that it would be easier to connect VBox from Host terminal via SSH then using Vbox GUI environment. I’ve found this process a little bit difficult and fortunately have solved it.

Now, I want to share my knowledge with you:

Note: <VBoxName> will be the name of the Virtual Box Machine. To find it type command “hostname” on guest machine.

1. Open up the terminal window on Host machine, and run the following:

$ VBoxManage setextradata <VBoxName> “VBoxInternal/Devices/pcnet/0/LUN#0/Config/ssh/HostPort” 2222

1. 1 If you encounter the following error(if not ignore this section),

VBoxManage: error: Could not find a registered machine named “VBoxName”...
do the following:
$ VBoxManage createvm –name <VBoxName> –register



$ VBoxManage setextradata <VMname> “VBoxInternal/Devices/pcnet/0/LUN#0/Config/ssh/HostPort” 2222


$ VBoxManage setextradata <VMname> “VBoxInternal/Devices/pcnet/0/LUN#0/Config/ssh/GuestPort” 22


$ VBoxManage setextradata <VMname> “VBoxInternal/Devices/pcnet/0/LUN#0/Config/ssh/Protocol” TCP

5.  Close the guest Machine Window (reboot is not enough)

Open up the terminal window on Host machine and run:

$ ssh -l username -p 2222 <localhost>

Where <localhost> is the name of the Host machine.

6.1  If you get the following error(if not ignore this section):

ssh-exchange-identification connection closed by remote host

One of the solution is to start ssh on both HOTS/GUEST machines:

$ /etc/init.d/sshd start

7. That is all, and one more hint: username by which you want to connect to the Guest machine must have password.