The easiest way to change the default route is to do the following:

1. Use smitty route->Remove Static Route or issue the route -f to flush the routing table.

2. You should see output to the screen informing you that routes are being removed.

3. Then issue the netstat -rn command. You should not see the default in the routing table.

4. Issue the smitty mkroute command. This is pretty straight forward and it will it will add

this default route to the ODM database and make it permanent even after a system reboot.

5. Issue another netstat -rn command, you should see your new default route.

1. Oracle TNS Listener Security

ENABLE VALID NODE CHECKING

Valid Node Checking allows or denies access from specified IP addresses to Oracle services. To enable Valid Node Checking, set the following parameters in $TNS_ADMIN/sqlnet.ora

tcp.validnode_checking = YES

tcp.invited_nodes = (X.X.X.X, hostname,)

tcp.excluded_nodes = (hostname, X.X.X.X …)

The first parameter turns on Valid Node Checking. The latter two parameters respectively specify the IP

Addresses or hostnames that are permitted to make or are denied from making network connections to Oracle services. Replace X.X.X.X with the middle-tiers’ IP addresses. Middle-tier applications include web servers, forms servers, reports servers, concurrent managers, discoverer, terminal servers, central administrator machines and any remote monitoring tool that uses SQLNet. Note, to use SQLNet clients such as sqlplus, toad, ADI from windows desktop, that desktop cannot use DHCP. Use a static IP address.

1.Change the GUEST user statement to the following in $CONFIG_FILE

<oa_user type=”GUEST”>
<username oa_var=”s_guest_user”>GUEST</username>
<password oa_var=”s_guest_pass”>GUEST</password>

Use upper case letters.

3. Run AP Tier Autoconfig.

4. Verify the $FND_TOP/secure/<host>.dbc file the entry for GUEST_USER_PWD is
set in the same letter case.

Patch fails with error “Error occurred in version checking”.

I was apply patch on the test instance, before applying on the production instance. While apply the patch I found this error “Error occurred in version checking”, I had searched on the internet I couldnt find the solution. My friend told me redowload the patch and try again. I had redownloaded the patch from the metalink. Then I had copied it to the test server through ftp and extracted the Patch. Then i had started patching through adpatch utility. It was completed successfully.

So, What may be the problem. First time I had downloaded the patch archive which was corrupted and some files where missing. Next time, it was ok. So, if the files are missing the adpatch will give this error “Error occurred in version checking”.

While i was Surfing the internet i had found a good site. I had recalled my Enigneering days where i used to study the subject.

What is NPTEL?

http://nptel.iitm.ac.in/

Objective

The main objective of NPTEL program is to enhance the quality of engineering education in the country by developing curriculum based video and web courses. This is being carried out by seven IITs and IISc Bangalore as a collaborative project. In the first phase of the project, supplementary content for 129 web courses in engineering/science and humanities have been developed. Each course contains materials that can be covered in depth in 40 or more lecture hours. In addition, 110 courses have been developed in video format, with each course comprising of approximately 40 or more one-hour lectures. In the next phase other premier institutions are also likely to participate in content creation.

http://nptel.iitm.ac.in/

5 useful HMC commands to help make managing your p5 systems easier.

1.) All slots configuration – identifies the type of adapter in each slot.

#lssyscfg -r sys -F name | while read mngsys; do lshwres -r io -rsubtype slot -F unit_phys_loc:phys_loc:lpar_name:description -header -m $mngsys | sed “s/^/$mngsys:/”; done

2.) CPU usage by LPAR’s:

#lssyscfg -r sys -F name | while read mngsys; do lshwres -r proc -level lpar -F lpar_name:curr_min_procs:curr_procs:curr_max_procs:pend_min_procs:pend_procs:pend_max_procs:run_procs -header -m $mngsys | sed “s/^/$mngsys:/”; done

3.) Memory usage by LPARs:

#lssyscfg -r sys -F name | while read mngsys; do lshwres -r mem -level lpar -F lpar_name:curr_min_mem:curr_mem:curr_max_mem:pend_min_mem:pend_mem:pend_max_mem:run_min_mem:run_mem -header -m $mngsys | sed “s/^/$mngsys:/”; done

4.) Total CPU configuration on managed P5 systems:

#lssyscfg -r sys -F name | while read mngsys; do lshwres -r proc -level sys -F configurable_sys_proc_units:curr_avail_sys_proc_units:pend_avail_sys_proc_units:installed_sys_proc_units:deconfig_sys_proc_units:min_proc_units_per_virtual_proc:max_virtual_procs_per_lpar -header -m $mngsys | sed “s/^/$mngsys:/”; done

5.) Total memory configuration on managed P5 systems:

#lssyscfg -r sys -F name | while read mngsys; do lshwres -r mem -level sys -F configurable_sys_mem:curr_avail_sys_mem:pend_avail_sys_mem:installed_sys_mem:deconfig_sys_mem:sys_firmware_mem:mem_region_size -header -m $mngsys | sed “s/^/$mngsys:/”; done

How-To Configure Gigabit Etherchannel

Note : This article is from http://www.linuxconfig.org/Linux_lvm_-_Logical_Volume_Manager

This article describes a basic logic behind a Linux logical volume manager by showing real examples of configuration and usage. Despite the fact that Debian Linux will be used for this tutorial, you can also apply the same command line syntax with other Linux distributions such as Red Hat, Mandriva, SuSe Linux and others.

This is what we are going to do

Create Partitions

For this Linux lvm example you need a unpartitioned hard disk /dev/sdb. First you need to create physical volumes. To do this you need partitions or a whole disk. It is possible to run pvcreate command on /dev/sdb, but I prefer to use partitions and from partitions I later create physical volumes.

Use your preferred partitioning tool to create partitions. In this example I have used cfdisk.

Partitions are ready to use.

Create physical volumes

Use the pvcreate command to create physical volumes.

# pvcreate /dev/sdb1<br /># pvcreate /dev/sdb2<br /></pre> <p>The pvdisplay command displays all physical volumes on your system. </p> <pre># pvdisplay<br /></pre> <p>Alternatively the following command should be used: </p> <pre># pvdisplay /dev/sdb1<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager05.jpg" class="image" title="Create physical volumes with pvcreate"><img alt="Create physical volumes with pvcreate" longdesc="/Image:Logicalvolumemanager05.jpg" src="http://www.linuxconfig.org/images/f/fc/Logicalvolumemanager05.jpg" width="508" height="368" /></a> </dd></dl> <a name="Create_Virtual_Group"></a><h2> <span class="mw-headline">Create Virtual Group</span></h2> <p>At this stage you need to create a virtual group which will serve as a container for your physical volumes. To create a virtual group with the name "mynew_vg" which will include /dev/sdb1 partition, you can issue the following command: </p> <pre># vgcreate mynew_vg /dev/sdb1<br /></pre> <p>To include both partitions at once you can use this command: </p> <pre># vgcreate mynew_vg /dev/sdb1 /dev/sdb2<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager06.jpg" class="image" title="Create Virtual Group"><img alt="Create Virtual Group" longdesc="/Image:Logicalvolumemanager06.jpg" src="http://www.linuxconfig.org/images/0/00/Logicalvolumemanager06.jpg" width="508" height="329" /></a> </dd></dl> <p>Feel free to add new physical volumes to a virtual group by using the vgextend command. </p> <pre># vgextend mynew_vg /dev/sdb2<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager07.jpg" class="image" title="virtual group extend"><img alt="virtual group extend" longdesc="/Image:Logicalvolumemanager07.jpg" src="http://www.linuxconfig.org/images/6/60/Logicalvolumemanager07.jpg" width="508" height="329" /></a> </dd></dl> <a name="Create_Logical_Volumes"></a><h2> <span class="mw-headline">Create Logical Volumes</span></h2> <p>From your big cake (virtual group) you can cut pieces (logical volumes) which are treated as a partitions for your linux system. To create a logical volume, named "vol01", with a size of 400 MB from the virtual group "mynew_vg" use the following command: </p> <ul><li> create a logical volume of size 400 MB -L 400 </li><li> create a logical volume of size 4 GB -L 4G </li></ul> <pre># lvcreate -L 400 -n vol01 mynew_vg<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager08.jpg" class="image" title="Create Logical Volumes"><img alt="Create Logical Volumes" longdesc="/Image:Logicalvolumemanager08.jpg" src="http://www.linuxconfig.org/images/e/e9/Logicalvolumemanager08.jpg" width="508" height="238" /></a> </dd></dl> <p>In this case you have created a logical volume with a size of 1GB and the name of vol02 </p> <pre># lvcreate -L 1000 -n vol02 mynew_vg<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager09.jpg" class="image" title="create logical vol01"><img alt="create logical vol01" longdesc="/Image:Logicalvolumemanager09.jpg" src="http://www.linuxconfig.org/images/a/a0/Logicalvolumemanager09.jpg" width="508" height="420" /></a> </dd></dl> <p>Note the free size in virtual group. </p> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager10.jpg" class="image" title="display virtual group"><img alt="display virtual group" longdesc="/Image:Logicalvolumemanager10.jpg" src="http://www.linuxconfig.org/images/6/6a/Logicalvolumemanager10.jpg" width="508" height="303" /></a> </dd></dl> <a name="Create_File_system_on_logical_volumes"></a><h2> <span class="mw-headline">Create File system on logical volumes</span></h2> <p>The logical volume is almost ready to use. All you need to do is to create a filesystem.: </p> <pre># mkfs.ext3 -m 0 /dev/mynew_vg/vol01<br /></pre> <p>the -m option specifies the percentage reserved for the super-user, set this to 0 if you wish not to waste any space, the default is 5%. </p> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager11.jpg" class="image" title="create file system"><img alt="create file system" longdesc="/Image:Logicalvolumemanager11.jpg" src="http://www.linuxconfig.org/images/4/46/Logicalvolumemanager11.jpg" width="508" height="277" /></a> </dd></dl> <a name="Edit_.2Fetc.2Ffstab"></a><h2> <span class="mw-headline">Edit /etc/fstab</span></h2> <p>Add a entry for your newly created logical volume into /etc/fstab </p> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager12.jpg" class="image" title="edit /etc/fstab"><img alt="edit /etc/fstab" longdesc="/Image:Logicalvolumemanager12.jpg" src="http://www.linuxconfig.org/images/4/45/Logicalvolumemanager12.jpg" width="508" height="277" /></a> </dd></dl> <a name="Mount_logical_volumes"></a><h3> <span class="mw-headline">Mount logical volumes</span></h3> <p>Before you mount do not forget to create a mount point. </p> <pre># mkdir /home/foobar<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager13.jpg" class="image" title="mount logical volumes"><img alt="mount logical volumes" longdesc="/Image:Logicalvolumemanager13.jpg" src="http://www.linuxconfig.org/images/a/ae/Logicalvolumemanager13.jpg" width="508" height="108" /></a> </dd></dl> <a name="Extend_logical_volume"></a><h2> <span class="mw-headline">Extend logical volume</span></h2> <p>The biggest advantage of logical volume manager is that you can extend your logical volumes any time you are running out of the space. To increase the size of a logical volume by another 800 MB you can run this command: </p> <pre># lvextend -L +800 /dev/mynew_vg/vol01<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager14.jpg" class="image" title="Image:logicalvolumemanager14.jpg"><img alt="Image:logicalvolumemanager14.jpg" longdesc="/Image:Logicalvolumemanager14.jpg" src="http://www.linuxconfig.org/images/b/b4/Logicalvolumemanager14.jpg" width="616" height="108" /></a> </dd></dl> <p>The command above does not actually increase the physical size of volume, to do that you need to: </p> <pre># resize2fs  /dev/mynew_vg/vol01<br /></pre> <p>Look at the figure below to see what problems you may encounter when extending a volume: </p> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager15.jpg" class="image" title="extend logical volume"><img alt="extend logical volume" longdesc="/Image:Logicalvolumemanager15.jpg" src="http://www.linuxconfig.org/images/6/67/Logicalvolumemanager15.jpg" width="616" height="537" /></a> </dd></dl> <a name="Remove_logical_volume"></a><h2> <span class="mw-headline">Remove logical volume</span></h2> <p>The command lvremove can be used to remove logical volumes. Make sure that before you attempt to remove logical volumes your logical volume does not have any valuable data stored on it, moreover make sure the volume is unmounted. </p> <pre># lvdisplay<br /></pre> <dl><dd><a href="http://www.linuxconfig.org/Image:Logicalvolumemanager16.jpg" class="image" title="display volume group"><img alt="display volume group" longdesc="/Image:Logicalvolumemanager16.jpg" src="http://www.linuxconfig.org/images/b/ba/Logicalvolumemanager16.jpg" width="616" height="394" /></a> </dd></dl> <pre># lvremove /dev/mynew_vg/vol02<br />

Other Topics

Discussion

Alexander.Orlov 10:35, 30 August 2007 (CDT) Any scenario ideas how/if/why LVM can be combined with GFS or OCFS? Will LVM become obsolete when the networks are fast enough to carry large amounts of data?

A FAQ list for the tutorial

• Is it possible/advisable to use LVM volumes as swap?
• Is it possible and/or advisable to use LVMs for external USB storage devices used for backups?
• Whether it is a good idea to use encrypted LVM volumes; especially encrypted LVM software containing volumes.

I have no answers to these questions yet. Alexander.Orlov 10:35, 30 August 2007 (CDT)

External Links

• Linux Documentation Project-HowTo

Technorati Tags: LINUX LVM

< Querying the RPM database >

As
you already know, the RPM database contains a list of all installed RPM
packages on your system. You can query this database to get info of the
packages on your Linux system. To query a single package, you use the -q option. For example, to query a package whose name is “software”:
# rpm -q software

After issuing this command, rpm either tells you the version of the package, or that the package isn’t installed.

If you want a list of all packages installed on your system, you’ll have to query all with -qa:
# rpm -qa

Most likely this list will be very long, so you’ll need a way to scroll it. The best way is to pipe the list to less:
# rpm -qa | less

If you’re looking for packages whose names contain a specific word, you can use grep
for finding those packages. For example, to get a list of all installed
RPM packages whose names contain the word “kde”, you could do something
like this:
# rpm -qa | grep kde

The above command makes rpm list all packages in its database and pass the list to grep. Then grep checks every line for “kde” and finally shows you all the lines that contain the word “kde”.

Raw Devices on RHEL 5 or OEL 5

Be aware that raw device technology had been deprecated in RedHat Linux 5 (RHEL5) and Oracle Enterprise Linux 5 OEL5). / Linux Kernel 2.6
Does this mean we cannot use Rawdevices in RHEL5 or OEL5? As always there’s a workaround to make this happen by means of UDEV technique and Oracle 11g & 10gR2 has options to configure components to access the block devices directly instead of rawdevices.Before we jump into the workaround, let see what exactly is missing at the O/S level w.r.to rawdevices in RHEL5 and OEL5,

1. /etc/sysconfig/rawdevices file doesn’t exist
2. /dev/raw doesn’t exist.
3. Service by the name “rawdevices” doesn’t exist.

Trying to run the command “service rawdevices restart” will result in “rawdevices: unrecognized service”.

Now lets see an example of configuring rawdevices in RHEL4 and RHEL5.

RHEL4

To map a rawdevice to a block device /dev/sdf1

Step 1: Make an entry in /etc/sysconfig/rawdevices file

/dev/raw/raw1 /dev/sdf1

Step 2: For the mapping to have immediate effect, restart the rawdevices service.

$>service rawdevices restart

Step 3: Change ownership to oracle user

$>chown oracle:dba /dev/raw/raw1

RHEL5 / OEL5

Step 1: Make an entry in /etc/udev/rules.d/60-raw.rules or create your own file viz., /etc/udev/rules.d/<any_no_above_60>-oracle-raw.rules (eg. 63-oracle-raw.rules)

ACTION==”add”, KERNEL==”sdf1″, RUN+=”/bin/raw /dev/raw/raw1 %N”

Step 2: For the mapping to have immediate effect, run below command

$>/bin/raw /dev/raw/raw1 /dev/sdf1

So if you or your system administrator have plans to upgrade an existing release of RHEL or OEL to RHEL5 / OEL5 or planning to perform a new installation of RAC on RHEL5 / OEL5, wherein rawdevices will be / are used, please do take additional care.

For more information you can refer to following
Metalink notes

RAC FAQ: 220970.1 (look for “What storage option should I use for RAC 10g on Linux? ASM / OCFS / Raw Devices / Block Devices / Ext3 ?”)
How to map raw device on RHEL5 and OEL5 – Note 443996.1
Linux 2.6 Kernel Deprecation Of Raw Devices – Note:357492.1
How to install Oracle Clusterware with shared storage on block devices – Note:401132.1

Blogs / Forums
http://frits.homelinux.com/wordpress/?p=27 – Thanks to Frits Hoogland for sharing this information and also for the article on configuring 11g with ASM on CentOS on VMware.
http://www.webservertalk.com/archive221-2007-5-1884747.html – Thanks to Rupan for the explanation on Rawdevices and Block Devices.

Technorati Tags: RAC VMWARE LINUX