Oracle & Linux Blog

- Moving a volume group to another system It is quite easy to move a whole volume group to another system if, for example, a user department acquires a new server. To do this we use the vgexport and vgimport commands. vgexport/vgimport is not necessary to move drives from one system to another. It is an administrative policy tool to prevent access to volumes in the time it takes to move them. 1. Unmount the file system First, make sure that no users are accessing files on the active volume, then unmount it. Here the mount point directory is /mnt/temp1. # unmount /mnt/temp1 2. Mark the volume group inactive Marking the volume group inactive removes it from the kernel and prevents any further activity on it.Here users is the volume group name. # vgchange -an users vgchange -- volume group "users" successfully deactivated 3. Export the volume group It is now necessary to export the volume group. This prevents it from bei...

wireless NIC is showing as wlan0 but I need to be appear as eth1. How can I rename wlan0 devices through udev as eth1? How do I change or rename eth0 as wan0 under Linux operating systems? A The best way to rename Ethernet devices is through udev. It is the device manager for the Linux kernel. Primarily, it manages device nodes in /dev. It is the successor of devfs and hotplug, which means that it handles /dev directory and all user space actions when adding/removing devices, including firmware load. The order of the network interfaces may be unpredictable under certain configurations. Between reboots it usually stays the same, but often after an upgrade to a new kernel or the addition or replacement of a network card (NIC) the order of all network interfaces changes. For example, what used to be rl0 now becomes wlan0 or what used to be eth0 now becoems eth2 or visa versa. Step #1: Find out the MAC address of the Ethernet device Type the following command: # ifconfig -...

 Issue Added a new partition to a disk that have some existing partitions already mounted. Can the new partition be used without reboot in RHEL6? New partition created with  fdisk  command is not visible in the OS. Resolution partprobe  was commonly used in RHEL 5 to inform the OS of partition table changes on the disk. In RHEL 6, it will only trigger the OS to update the partitions on a disk that none of its partitions are in use (e.g. mounted). If any partition on a disk is in use,  partprobe  will not trigger the OS to update partitions in the system because it is considered unsafe in some situations. So in general we would suggest: Unmount all the partitions of the disk before modifying the partition table on the disk, and then run  partprobe  to update the partitions in system. If this is not possible (e.g. the mounted partition is a system partition), reboot the system after modifying the partition table. The partitions in...

To switch to a graphical environment, you might need to install extra software from a  repository . You can access Red Hat Enterprise Linux repositories with your Red Hat Network subscription through the Internet or use a Red Hat Enterprise Linux installation DVD as a repository.  If you installed using a text login and wish to switch to a graphical login, follow this procedure. If you are not already root, switch users to the  root  account: su - Provide the administrator password when prompted. If you have not already done so, install the  X Window System  and a graphical desktop environment. For example, to install the GNOME desktop environment, use this command: yum groupinstall "X Window System" Desktop To install the KDE desktop environment, use: yum groupinstall "X Window System" "KDE Desktop" This step may take some time as your Red Hat Enterprise Linux system downloads and installs additional software. You may be asked to...

This demo is to show issues during Oracle 11g Database cloning. Oracle Version: 11.2.0.4 Operating System: Oracle Enterprise Linux 6.5 I have two nodes : rac1 ( Catalog Database )  & rac2 ( Target Database ) Target Database Name: DB002 Catalog DB Name: DB001 Catalog TNS service name: SN001 Auxiliary DB Name: clone Auxiliary TNS Service Name: clone Catalog TNS entry:  SN001 =   (DESCRIPTION =     (ADDRESS = (PROTOCOL = TCP)(HOST = rac1)(PORT = 1621))     (CONNECT_DATA =       (SERVER = DEDICATED)       (SERVICE_NAME = SN001)     )   ) Auxiliary TNS Entry: CLONE =   (DESCRIPTION =     (ADDRESS_LIST =       (ADDRESS = (PROTOCOL = TCP)(HOST = rac1.localdomain)(PORT = 1721))     )     (CONNECT_DATA =       (SERVICE_NAME = clone)     )   ) We are going to create the Auxiliary inst...