Calculate the Efficiency of your Logical Volume in AIX

# lslv -l hd2 : Command to view the LV fragmenation.

hd2:/usr
PV                COPIES      IN BAND        DISTRIBUTION
hdisk0        114:000:000        22%           000:042:026:000:046

COPIES: 114:000:000

114 : No.of LP's in the first copy.
000 : NO LP's,so no secound copy.
000 : NO LP's,so no third copy.

Therefore the LV is not mirrored.

IN BAND : Shows how well the Intrapolicy and the attribute of the LV is followed.

22%, higher the percentage, the better the allocation efficiency.

Each logical volume has its own intrapolicy. If the operating system cannot meet this requirement, it chooses the best way to meet the requirements.

DISTRIBUTION : edge : middle : center : inner-middle : inner-edge

               000     042       026         000         046            -----> 114 LP.
Since the LV was created with the intra allocation policy "Center"----------->No.of LP's at the center is "26"--->So, 26/(0+42+26+0+46) = 0.2280 * 100 = 22 %

HACMP 2 Node Cluster Steps- Part II

Resource Configuration:

# smitty hacmp --> Extended Configuration --> Extended Resource Configuration --> HACMP Extended Resource Configuration--> Configure HACMP Application and Configure HACMP Service IP Labels and IP Address.

In this wizard we select the option "Configure HACMP Application" to create an Application Server and provide the "Startup" and "Stop" scrip.

We select the "Configure HACMP Service IP Lables and IP Address" to add the "Service IP" to the cluster Network which we created.

So, from "Configure HACMP Service IP Labels and IP Address" --> "Add a Service IP Label/Address"
and select "Configurable on Multiple Nodes" and select the network which we created "net_ether_##" and select the service ip and press "Enter".

The above process binds the "Service IP" with the "Cluster Network".

Next we proceed with Resource Group Configuration:

# smitty hacmp --> Extended Configuration --> Extended Resource Configuration --> HACMP Extended Resource Group Configuration --> Add a Reource Group.

Enter the Resource Group Name, Participating Nodes (Node 1 and Node 2 and set the cluster policy and "Enter".

# smitty hacmp --> Extended Configuration --> Extended Resource Configuration --> HACMP Extended Resource Group Configuration --> Change/Show the attributes of Resource Group.

Select the "RG" which you have selected. In this window you have select the "Service IP" and "Application Server" which we configured earlier.

Now do a "Discovery of cluster"

Next we see configuration of Volume Group:

The resource group which hold the resource should be placed in the shared volume group in terms of a shared file system via shared logica volume. So that the application which binds to the service ip will be available across all the nodes on the cluster.

# smitty hacmp --> System Management (C-SPOC) --> Hacmp Logical Volume Management --> Shared Volume Group --> Create a Shared Volume Group --> Select the node ( Node1and Node2) --> Select the PV ID--> Enter the Volume Group Name / Major Number and Enter the size of PP and Enter.

Create Shared Logical Volume:

# smitty hacmp --> System Management (C-SPOC) --> Hacmp Logical Volume Management --> Shared Logical Volume --> Add a Shared Logical Volume --> Select the Volume Group Name --> Select the Physica Volume --> Enter the Logical Volume Name and No.of LP's and Enter.

Create Shared File System:

# smitty hacmp --> System Management (C-SPOC) --> Hacmp Logical Volume Management --> Shared File System --> Journal File System --> Add a Journal Filesystem on a Previously Defined Logical Volume -->Add a standard Journaled File System --> Select the Shared Logical Volume -->Enter the Mount Point and Enter.

We are good to go now.

Finally, perform Verification and Syncronization:

# smitty hacmp --> Extended Configuration --> Extended Verification and Syncronization.

Verify and Syncronize on both the nodes ( Node1 and 2) and Enter.

Cluster Configuration is Over.

HACMP 2 Node Cluster Steps- Part I

Cluster Configuration between Node A and  Node B.


Node A :


Bootip : 192.168.1.1
Standby ip : 192.168.1.2
Persistent ip : 192.168.1.3
Service ip : 10.0.0.1


Node B:


Bootip : 192.168.2.1
Standby ip : 192.168.2.2
Persistent ip : 192.168.2.3
Service ip : 10.0.0.2




Ensure that above entries are added to the "/etc/hosts" of Node A and Node B.


We assume that the required file sets for HACMP are already installed on the nodes and both the nodes are restarted.


1) Configure Cluster (Cluster Name: test_cluster)
2) Node Configuration : (Node A and Node B).
3) Network Configuration.
4) Resource Configuration.
5) Verification and Syncronization.


Configure Cluster:


# smitty hacmp --> Extended Configuration --> Extended Topology Configuration --> Configure Cluster-->Add/Change/Show Hacmp Cluster


Enter the name of the cluster "test_cluster" and Enter.


Configuration of Nodes:


# smitty hacmp --> Extended Configuration --> Extended Topology Configuration --> Configure HACMP Nodes--> Add a node to HACMP Cluster.


Select Node Name "Node_A_test_cluster" and enter communcation path to the node as boot ip of node A which "192.168.1.1" and repeat the same for node B "Node_B_test_cluster" and the communication path to the ndoe "192.168.2.1".


Discovery of Configured Nodes:


Now we are going to do a discovery of the nodes added to the cluster.


# smitty hacmp --> Extended Configuration --> Discover HACMP-related Information from Configured Nodes
Network Configuration:


# smitty hacmp --> Extended Configuration --> Extended Topology Configuration--> Configure HACMP Networks --> Add a Network to the cluster --> Select "ether" and Enter.


Enter:


Network Name : Default name appear "net_ether_##"
Network Type : ether
Netmask : Mask value appears
Enable IP Address Takeover : Select "Yes" if you opt for "IPAT over Alias" Method.


Enter.


Adding Communication devices to the cluster


This as the name implies we need to add the communication devices to the cluster. Device means "Node A" and "Node B" and how they communicate with each other. The communication happens via "Node_A and Node_B (boot_ip and standby ip).


# smitty hacmp --> Extended Configuration --> Extended Topology Configuration--> Configure HACMP Communication Interfaces/Devices --> Add communication interfaces/device--> Add a Discovered Communication Interface and Devices and select "Communication Interfaces"


Now select the network which you have configure "net_ether_##". Which in turn opens a window with the "Node_A_test_cluster" and "Node_B_test_cluster" [bootip and standby ip]
select the ip (totally 4) that is 2 per node and "Enter".


Cont........Part II

HACMP Overview

What is HACMP in AIX ?

High Availability Cluster Multi Processing, the term which mainly foucs on the availability of applications. This term means a lot when we speak about of "Fault Tolerant" FT. Fault Tolerant as the name implies, which has the ability to persist across any hardware failure like CPU, Memory, Interface and others using redundant components. By this model the fault tolerant machine is capable of providing high availability for an application at any given time.

But the draw back for "Fault Tolerant" methodology is, Since it relies of redundant components. The cost factor is high. This has lead to the development of "HA" High Availability. Which is capable of providing high availability for an application by sharing of application across multiple nodes.

So how is differs from FT,

FT : High Cost Involved
HA: Compartively Less.

FT : No Down Time Required.
HA: Less Down Time Required.

Operating System Cloning in IBM AIX and HP Unix

This post shows how to do cloning of Operating System. Since we already discussed abt cloning of Operating System (alt_disk_copy) method. Will straight away discuss about hp unix cloning.

In hp unix we use a utility called "Dynamic Root Disk" [DRD] to do cloning of the disk.

1) # uname -a : Check the version of Hp Unix.

2) # model : Check the model of the machine.

3) # swlist -l product -l bundle | grep -i dynamic : Ensure the DRD software is installed on the box.

4) # strings /etc/lvmtab : Find out the disk on which the OS intalled.

5) # diskinfo -v /dev/rdsk/c#t#d# : Command to find the size of the disk.

6) # ioscan -funC disk : Look for the free disk. Select the disk of size which is equal to OS disk.

7) # pvdisplay -v /dev/rdsk/c#t#d# : Ensure the LVM status of the disk is "No". The physical volume should not be a part of any  LVM structure.

8) # drd clone -p  -v -t /dev/dsk/c#t#d# : Command to take a preview of the clone and analyze the disk capability to ensure that it can hold the clone. If it is successful..

9) # drd clone -v -t /dev/dsk/c#t#d# : Command to clone the disk. It take 30 minutes of time.

The default name of the Operating System volume group is called as "vg##" and the cloned one is called "drd##".

10) # bdf : Command to verify the cloned Operating System.

11) # drd umount : Command to un mount the cloned Operating System.

Virtual SCSI Mapping Through HMC rather than "mkvdev" CLI

This post shows an easy wat to perform mapping of disk between the Virutal Server and Virtal Client though Hardware Management Console. Rather than CLI using "mkvdev".

Disadvantage of thie method. Only directy mapping of the disk could be made rather than mapping a logical volume or a filesystem are not supported in this method. In those case we need to go back "mkvdev" mode for the mapping.

So we assume that a disk has been mapped the VIO_Server from the SAN Side.

Login into HMC-->System Management-->Server(Managed System to which the VIO_Server and VIO_Client Belongs to)-->Configuration-->Virtual Resources-->Virtual Storage Management.

This opens a windows like below.

In the window, on the left hand top corner you would find a drop down called "VIOS". Select the appropriate VIO_Server. This would list all the physical volumes available on the VIO_Server. To begin with the mapping. Select the disk that you would like to assign and click on "Modify Assignment" on the left hand bottom corner.

This the next window that will open upon selecting "Modify Assignment". Select the appropritate "Virtual SCSI Server Adapter" (vhost#) and click "OK".

Now the mapping is done.

Cloning rootvg to external disk_AIX_ : Mapping to VIO_Client: Part III

VIO_Server

$ lsdev -virtual or $ lsdev | grep "vhost*" or $ lsdev -type adapter : List all the virtual adapters on the VIO_Server.

$ lsmap -vadapter vhost* : Show the mapping of the Virtual SCSI Server Adapter.

$ lspv : Command to list the Physical Volumes.

$ mkvdev -vdev hdisk# -vadapter vhost# : Command to provide mapping between the virtual SCSI Server and Client Adapter.

$ lsmap -vadapter vhost : Command to verify the mapping has been done or not.

VIO_Client:

Now boot the disk through SMS Mode from HMC. Which would boot the client from the "cloned" disk. Upon successful installation of the Operating System. Login into the client.

# lspv : List all the physical volume.