Second set of VMWare based interview questions..
Check out our part I, in case if you haven’t:
First set of VMware based interview questions..
VMware DRS (Distributed Resource Scheduler), sums up computing capacity across a collection of servers and is allocated to the VM’s based on its needs and requirements. This allows the VM’s to recieve the resources dynamically, when it is required. If in case a VM experiences an increase in load, DRS automatically allocates additional resources, without affecting other VM’s. This is done by continous monitoring of resources by VMware DRS.
FT or Fault Tolerance, provides continuous availability for the protected virtual machines, in the event of a VM/hardware failure. It ensures zero downtime preventing data loss and here’s where FT differs from HA. This is done by creating a live shadow instance of a VM (running on another host), referred as the Secondary VM, that is always up-to-date with the original VM, referred as the Primary VM. FT works as below:
Before reading this post, it is recommended to read this article, which will give you an idea on what HA is.
Types of host failures:
Three types of host failure are detected:
- Host failing to function
- Host becoming isolated from network
- Host losing network connectivity with the master host
HA (High Availability), as the name implies is a feature to protect the hosts and its virtual machines from unplanned downtime. Else, HA minimizes downtime. Though by definition it is simple, this has got a number of process to get this done in a very effective way.
Sharing a bit of information that could help someone sometime. If you’ve a VMWare environment, you may need to set license for your Esxi hosts. This could be done with the help of vsphere client as well as using command line. Let us find out how this can be done in both the ways..
While trying to start-up a restored Windows 2012 server, it thrown an error as shown below. If you come across such a situation sometime, this article helps you to solve this issue. The same issue can also be applied in the case of Windows 8 operating system too.
Networking related shell commands
esxcli network nic list–List VMNIC’s
esxcli network vswitch standard list–List vSwitches
esxcli network vswitch dvs vmware list–List vDistributed Switches
esxcli network vswitch standard portgroup list–List vSwitch port groups
Esxi related shell commands
chkconfig –list–Lists all services
/sbin/service.sh restart–Restart all management services
/etc/init.d/servicename restart–Restart single service
vicfg-cfgbackup –s /tmp/hostname.cfgbak–Backup host configuration
esxcfg-info > /tmp/esxcfg-info.txt–Export detailed configuration file