How to use VMDK sharing for Guest OS clustering

Operating system clustering is one of the major and popular high availability mechanism in system infrastructure products. Advantage of the os clustering is it can identify the application level failure.

As a systems administrators most of the time we may need to work with MS windows failover clusters. Most of the file servers and SQL clusters are depend on this failover cluster technology. Most of the situation one of the main requirement is this failover cluster is shared lus/disk. Earlier most of the time we sued to have minimum two physical servers for this cluster operation which is directly connect to SAN device(Shared storage). But to get the benefits of virtualization platform and reduce the cost , now we have to use same cluster features on top of the virtualization platform.

1. In my below example Im using two test virtual machines.

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2. Now we need to add new scsi controller per this vm


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Reclaim disk space on VMware thin disk

    In a vSphere based virtualization environment we can mainly use two disk types(Thick & Thin).I hope you all know the difference between these two.

    To optimize our shared/Direct attached storage we can use thin disk. But the problem is even we delete the data from os level . It will not reclaim automatically from the storage.

    To overcome this issue we have two options.

    1. Use third party tool(if it’s a Windows we can use sdelete) to zero-out the disk blocks and using vmkfstools we can shrink the disk
    2. Storage vMotion the virtual machine or VMDK to a datastore formatted with a different block size

    In this article we are going to showcase how to use sdelete & vmkfstools to this operation

    1.This vm we have two thin disks. We will use second disk for the our test case. Capacity of the disk is 3GB

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    1. From the datastore we can see 80.47 GB free space

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vCenter appliace–how to manage services

The easiest way to manage services in vCenter appliance is using putty tool.First we need to open ssh session with vCenter appliance.

List all the services

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Check the status of all the services

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vCenter appliace–how to manage services

The easiest way to manage services in vCenter appliance is using putty tool.First we need to open ssh session with vCenter appliance.

List all the services

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Check the status of all the services

Continue reading “vCenter appliace–how to manage services”

VMware-Migrate iscsi traffic from standard switch to distribute switch

Option01

When we are having some extra network adapsters. We can follow below steps.

  1. In thi slab environment, we have two nics for existing iscsi connection using Vmware standard swtich.
    1. Esx01.mobilab.local have one standard switch configured for iscsi traffic

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  1. Now we have configured vmware distributed switch and added vmnic4 & vmnic5 to this distributed switch & all the ip address configured.

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VMVware vswitch load balancing methods

Load balancing is one of the most important thing in a virtual world. Because we are using few NICs for receiving & sending a data of multiple virtual machines. There are few policies in vmware load balancing . We will take one by one and lets have a look.

Route based on originating virtual port ID

Example

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In this vswitch I have two nics allocated.

And I have three virtual machines as bellows

 

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Server A have one Nic,Server B have two Nics & Server C have one Nic.

Route based on originating virtual port ID works like round robin. Server A nic will be use physical vmnic4 for passing the traffic.

Server A first nic will be use vmnic5 and second nic will be use vmnic4

Server C have only one nic and it will use vmnic4.

In this load balancing mechanism it doesn’t measure any other things. That is the main disadvantage of this, but we don’t have to do any modifications to the physical network environment.

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