An interesting feature in vCloud Director networking is the capability of creating a fenced vApp. Basically, it’s like having an extra (in case you have one for Organization network which means routed) vShield router and firewall on the edge of vApp.
One of the coolest applications for fenced vApps is when you want to have identical machines (same IP and MAC) in your vDC; it means when you want to do a fast clone without customizing guest OS by changing IP’s and names, … In this case vApps are completely isolated while they can have connection to External networks or perhaps internet! See here for a how-to about creating fenced vApp.
After you created a fenced vApp, you will notice that the IP addresses in the vApp are in the same subnet with Organization Network (see the picture above), although a NAT gateway is operating between the vApp and Organization network. So when you want to do a DNAT (Destination NAT), there are 2 places you should configure. In the picture above, suppose you want to give access to a VM with IP 192.168.0.45 in Fenced vApp from External Network. Assume that Edge 1 got IP 192.168.0.3 (specified while fencing). First, you need to create appropriate rules in Edge Gateway of Organization Network, Edge 2 (if there is any) to NAT and open ports for the IP address of Edge 1 (192.168.0.3)
Next step, you need to do NAT and open ports from Edge 1 to specific VM but this configuration is not in Edge Gateways of vDC (unlike Edge 2) but can be found in Networking Tab of the vApp itself.
Click on the vApp, go to Networking tab,
right click on the selected network and choose ‘Configure Services’. there, you can define appropriate NAT and firewall rules.
Having templates and cloning VM’s can be very handy for fast deployment. Suppose that you want to deploy an instance of a sophisticated Web application consisting of different functional servers like database, web, mail, messaging, etc. It is desirable to clone the whole application, saving lots of time to configure each server and establish connectivity between them. VMware enables us to do this by using vApp templates. vApp templates are also available in vCloud Director.
However, when it comes to Microsoft SQL Server, an issue is raised when you rename the server during cloning or customize operating system in vCloud! It’s because SQL server contains some internal databases (like master) and metadata that store system name and working with SQL server in this situation will cause problems. To prevent this issue, you can do the following:
1) Enable a sysadmin SQL account (like ‘sa’) before cloning.
2) After clone, login to new SQL Server using a non-Windows sysadmin (like ‘sa’)
3) issue the following commands in a Query window:
exec sp_dropserver ‘OldserverName’
exec sp_addserver ‘NewServerName’, ‘LOCAL’
4) Restart SQL Server services
In VMware vSphere client (native and web client), sometimes you get this message in Summary tab of a host: “Configuration Issues: Quick stats on Host ‘xyz’ is not up-to-date”
Most of the times this message disappears after a while but sometimes it bothers for a long time. In those cases, a quick ‘Reconfigure for vSphere HA’ may clear the message.
When you upgrade your VMware environment to version 5.5. remember to upgrade your distributed vSwitch as well; it will not be done automatically. In this way, you can utilize new features in dvSwitch 5.5, including:
The upgrade process is fairly easy and the good thing is that according to VMware documentation, it is non-disruptive which means there is no outage and no host and VM will get down or experience issues. Find your distributed vSwitch either in vSphere Client or Web client, right click and do upgrade.
To install VMware vSphere Big Data Extensions 1.1, if you satisfy the requirements mentioned in vmware document, go ahead with installation by deploying Big Data Extensions OVA as documented. But attention that:
- Better to create a specific Resource Pool for your Big Data Cluster and specify the total amount of resources you want to assign and apply possible limits.
- Create a port group dedicated to Big Data Extensions as a communication link between management servers and working VMs.
- When deploying Big Data Extensions Management server (OVA), ‘setup networks’ asks you to assign a destination port group. Note that: Management Network will use this network to communicate with vCenter server. So, if you use VLAN tags, the port group should be in the same VLAN (use same VLAN id) with vCenter network. If vCenter can not see Big Data Management server and vice versa, integration will not be made properly.
- In ‘Customize template’ step, there are 2 important settings: SSO service and Management Server IP address. So, from right-pane open ‘VC SSO Lookup Service URL’ and ‘Management Server Networks Settings’. Enter appropriate values. For SSO Lookup Service URL, use vCenter server with the same format (if you didn’t change defaults), I mean port 7444/lookupservice/sdk. Use FQDN of vCenter and not IP address or certificate will not be accepted and you will see errors for connecting Big Data Extensions plugin to Serengeti server in the future.
Nowadays Big Data is everywhere. Many are talking about it and they are enthusiastic to deploy a Big Data instance in their environments. Installation and deployment can be difficult though. The fact is that there is no official mature Big Data standard and lots of open source standards are being developed, sometimes independently. Even if we accept Apache Hadoop as the dominant standard of Big Data, implementing Hadoop is a big challenge for IT departments. For example, according to this article: In addition to the technical challenges of deploying large-scale Hadoop systems and applications, another issue Manor cited is that IT operations often work in silos, with separate teams handling systems administration, database administration, storage, networking, security and application development. That approach can lead to problems in managing Hadoop clusters.
And it’s exactly where Virtualization, Cloud and SDN can help: integrating multiple administration tasks in a unified control center. And VMware did this beautifully by putting together all required Hadoop components in a package to create Clusters and control and scale the Hadoop Clusters by using VMware vSphere Big Data Extensions. Hadoop clusters which are created by vSphere Big Data Extensions are scalable, elastic and flexible. You can easily separate compute and data nodes or increase the number of working machines and so on. vSphere Big Data Extensions utilizes the open source project Serengeti that was initiated by VMware to implement Hadoop on a virtual platform. Serengeti or better to say VMware vSphere Big Data Extensions deploys HDFS, MapReduce, Pig, Hive and HBase on vSphere infrastructure.
You can find general installation instructions here, but there are some implementation tips which will help in vSphere Big Data Extensions installation. In my upcoming posts I will show the required steps and important considerations during installation.
Sometimes you may notice that your customization of a VM fails when you provision VM from template or import it from vSphere; for example Computer Name may not be changed or IP address can not be assigned.
There are a couple of documents about troubleshooting guest operating system customization in VMware kb: for vCloud Director and vCenter. But none of them worked in my specific case, so I’m sharing something important in Windows OS’s. This hint will be useful especially when you see this error in: C:\Windows\Temp\vmware-inc\guestcust.Log:
“Command Execution failed with exist code: 1, output: ‘The service can not be started.’ ”
Since Windows administrators tend to disable some unnecessary services to harden security, we should know which services are necessary for VMware, if there is any. In fact, a number of Windows services should be enabled and started so that VMware customization works properly. The necessary services are:
- DNS Client
- DHCP Client
- TCP/IP NetBIOS Helper
So, if you face the same issue, besides viewing Logs on VM, check these services as well.