Depending on how much you spent creating your lab, you may find yourself running out of disk space sooner rather than later. This can be a frustrating experience, so I decided to do a quick post about several ways you can deal with this issue.
1. Create Linked Clones
When working with limited disk space (especially if it is on SSD’s), you will want to create a gold/master VM that you can save as a template as well as use as the base for your linked clones. If you don’t know what Linked-Clones are, essentially you are creating a pure “STANDARD” VM that can be used as a base VM for other future virtual machines. When you need another VM, instead of creating a new full VM that is, lets say, 40GB, you create a linked-clone, which will reference the base bits of your STANDARD VM that you created earlier. Your disk size will only grow with the deltas between the standard and the new VM. When you have your base VM’s running on SSD you can run many more VMs from the same standard bits without seeing performance degradation. If you usually have 5+ Server 2008 VMs running in your lab, you are essentially cutting your disk usage down by (the size GB of the installation of server 2008 with updates * # of VMs running). This savings adds up quickly.
Another way to deal with the issue of low disk space is to use deduplication. There are several virtual appliances out there that you can use for free that offer deduplication. Deduplication speaks for itself in that these appliances will look through the blocks of data in their datastores and deduplicate any bits that show up more than one. Pointers are placed that allow the data to continue being usable while keeping your disk usage to an absolute minimum. I have personally tried Nexentastor and used that for quite a while. If you are backing up your VM’s, almost all VM backup solutions integrate deduplication into their products: Arkeia, Veeam, VMturbo, etc.
3. Be frugal in your storage use
Many of you, like me, probably have multiple copies of the same downloads and ISO’s scattered between multiple computers, flash drives, NAS’s, etc. I find myself being sloppy time and time again by pulling an installer into a VM and after using it, I DON’T DELETE IT! yeah, that adds up too! Create a network share that is accessible in your lab and make sure to keep your files there. I prefer to add an NFS export as well and connect it to my hosts so that my ISOs can be mounted from there without having to upload any of them to another datastore.
4. Use Thin Provisioning
This should have been the very first bullet. As I started writing this I figured that this would be a no-brainer, but then I decided, since it really is important, to add it in anyways. There are very few reasons that could be keeping you from running everything thin. If you have all the storage your heart desires then be my guest. Chances are, if you are reading this blog post it means that you are not one of those people :).
5. Purchase more storage
Last but not least, if the above 4 options still do not give you the amount of flexibility and wiggle-room you need, then it’s probably pretty safe to say that you didn’t have enough space to begin with. Decide if you want to install more storage locally or invest in a NAS. I prefer the Synology NAS’s hands-down, no questions asked. Yes, they are more expensive, but you get what you pay for. If you do purchase a NAS you will also want to decide if you are going for extra speed or larger drives. I prefer a mixture of SATA Western Digital Reds with a few SSD’s. The Reds hold installers and other VM’s like my active directory VM that doesn’t do much data transfer.
Hopefully this article has been beneficial. What have you done to deal with limited disk space in your labs?