Tuesday, September 18, 2012

vSphere Replication hostname reverts to localhost.localdom


When implementing Site Recovery Manager (SRM) with VMware Replication solution, you must have to deploy one vSphere Replication Management Server (VRMS) at each site and at least one vSphere Replication Server (VRS).

As you would normally do with any device on your environment, you went to change it’s hostname and assign a unique name to each one of these components.

This task can be easily accomplish through the web interface of them.



But, once you reboot them, you will realize it reverts it’s name back to localhost.localdom.

So, How do we make VRMS and VRS to keep theirs hostname ?

On VRMS it’s an easier task.
During reboot, there’s a start up scripts which tries to solve it’s own IP address.
If it cannot resolve it’s DNS, it reverts it’s name to localhost.localdom.
To fix that you just need to create a reverse PTR entry on DNS for yours appliances.

VRS has the same start up script, but the problem is there are some missing packages, so it fails to set up it’s new name and reverts back to localhost.localdom.
To fix that you just need to install the missing RPMs.

As you can see bellow, the appliances are SuseLinux Enterprise Server 11, you could image that it’s just go to the Suse webpage and download them, right ?
Well, good look with that, I expend hours and could not find them there.


 The missing packages are bind-utils and bind-libs, but libcap is a dependency of those packages, so download and install it as well.
You can double check running: rpm -q -a bind-\*

I could find the files elsewhere. I will publish them here to make our lifes easier.
Use them at your own risk.


 
Once you downloaded them, copy it to a location where the appliances have access.
Then, just install the RPMs. The syntax is rpm –i “rpm_package”

Now you can change it’s hostname and it will stick after reboot.

Thursday, September 6, 2012

NIOC prioritizing specific VLANs/Subnets



It’s not unusual when presenting the NIOC feature for a client, they ask me:
 Is it possible to prioritizing the traffic of just a group of VMs ?

The answer is yes !!!
 
But first let’s remember what NIOC is:

Network I/O Control (NIOC) is a feature on the Distributed Virtual Switches (vDS) that when the hosts detects a congestion on it's network card, it will then starts to prioritize the traffic flowing from it.
To prioritize it's network traffic, it uses the SHARES concept (the same concept we are used to with vCPU and memory shares of a VM).

You can configure the shares on the following traffic types:

- vMotion
- iSCSI
- FT logging
- Management
- NFS (Network File System)
- Virtual machine traffic
- vSphere Replication traffic

That’s when the client realizes all the traffic for the virtual machines will get the same priority and then the inevitable question pops up.

Luck of us that the NIOC has been enhanced with vSphere 5.0 and now it includes the capability of creating a user defined network resource pool.
With that in mind, you can create a new network resource pool, give it a higher share than the Virtual machine traffic and associate this resource pool with a PortGroup.

If all your VMS are on the same Port Group you wound not be able to prioritize the atraffic among them.
You will need to segregate your VM's traffic, creating new PortGroups/ VLANs, let’s say for critical VMs, or databases then you can give them a higher priority over the others.

Let’s see how to configure it.

- On vCenter, go to Home/Networking
- select the vDS that has the portgroup you want prioritize.
Make sure the NIOC is enable.
- click on “New Network Resource Pool”



- add a name, a description (optional) and adjust the share as you wish.

 - click OK

as you can see the New Network Resource Pool has been created



It’s time to associate this resource pool with a Port Group
- click on Manage Port Groups



- Select the Port Group you want to change and on the Network Resource Pool Column select the Network Resource Pool you just created. Click OK



There’s also another way to associate a Port Group with a Resource Pool.

- Right Click on the Port Group you want to change and select Edit Settings


- Select Resource Allocation
- Change it for the desired Network Resource Pool.


 - Click OK.

Now you can give the network priority your VMs deserves.




Who am I

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I’m and IT specialist with over 15 years of experience, working from IT infraestructure to management products, troubleshooting and project management skills from medium to large environments. Nowadays I'm working for VMware as a Senior Consultant, helping customers to embrace the Cloud Era and make them succefully on this journay. Despite the fact I'm a VMware employee these postings reflect my own opnion and do not represents VMware's position, strategies or opinios.

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