Mistake #6: Failing to Record Log Time Entries
Do you know when the entries in the logs happened? Do you have a centralized time synchronization mechanism? I hope you have some kind of Network Time Protocol (NTP) implementation, or you rely on the NTP from some reliable source in your organization or on the internet. Remember that NTP, meaning correct timing implementation, is also important if you have logs that are being saved.
Mistake #7: Falling for All the Bells and Whistles
Some virtualization products allow you to go to the Internet on the host. To me, this is an absolute “no” because if you are on the Internet and downloading possible bad applications, it could cause the host to crash and bring every VM on it down with it. The more restricted host I have the better.
Mistake #8: Failing to have a Backup Plan
Let’s say that something happens, and your host or VM crashes. What are your plans then? What kind of work was the VM doing? Can you afford to live without this VM? Do you have another machine that will take over in case the primary machine fails? Consider the downtime involved; if you have a standby machine, it will kick in within moments of when the original VM goes down. But with fault tolerance, the VM will have to be restarted on a different host.
Mistake #9: Improper Storage Allocation
A common issue folks run into is committing a certain amount of disk storage for the VMs but never really filling up the virtual drive. If you don’t have a need for it, maybe you shouldn’t pre-allocate that storage. For example, VMware’s virtualization product allows you to allocate the storage on demand. This is called the thin provisioning mechanism. Remember to be careful not to over-commit some storage drive. What would happen if all your VMs started growing and get near the maximum space allocated to them? Do you have enough space available for all of them?
Mistake #10: Poorly Planned Host Management Solution
How are you managing your ESXi hosts from VMware? How are you managing your VMs on these ESXi hosts? If you only have one or two hosts, then maybe you can connect directly to your ESXi host to mange them, but what if you have many ESXi hosts? If that’s the case, then you need some kind of a central management solution. In case of VMware, you have the vCenter implementation. This will definitely make managing your ESXi hosts.
This post is excerpted and reprinted with permission from 14 Common Virtualization Mistakes – And How To Avoid Them by Dheeraj (Raj) Tolani