Partitioning a VM host
 

I am setting up a v-lab on a DL360 G5. I would appreciate some input as to the correct way to partition the drives. I will be installing CentOS 6 w/KVM. I plan to run the machine "headless" and I am trying to keep the resource overhead as low as possible.

I have already made it all work with a 250MB /boot partition and the rest of my space in one massive /root partition. I am looking for the "correct" way and why. I usually follow the setup suggested in Redhat's documentation. It only calls for a 4-5GB /var partition though and apparently that is where the VMs go. So, do I just make a huge /var partition? What size do you guys recommend for the others, considering that I want the native OS's footprint to be as small as possible?

I have 3 drives available, a 36GB and two 146GB ones.

I someday hope to be a system administrator and I am trying to learn good practices. I could just put it all in /root, but I would like to know how a large company would set it up.

well a system administrator won't get that far if they don't know the difference between / and /root. ;-) /root is only for the root users files, you would never dedicated any significant space to this.

I wouldn't just increase /var as /var does all sorts of different things, instead I'd think about dedicate and LVM volume to /var/lib/libvirt for the virtual machine details. if you're only using the base os as a host, you'll not need any space, so IF you aren't building in resilience, i'd put the OS on the 36gb drive, and the rest as /var/lib/libvirt

But how a large company would set it up? Depends on the company. Many would be forced to use a single layout that works really badly but are unable to deviate from it for a thousand different reasons. Other large companies will have sysadmins who don't care and just accept all the defaults.

Ok, so what about LVMs? Do I make a /boot partition on the 36GB drive and then put the rest of the space on that drive as well as the other two drives into a physical volumes?

Should I put /var/lib/libvirt in a separate Volume Group?

I've favored putting OS in one VG and application in another for clarity personally, so as you seem to have plenty of space, yes, I'd have an LVCentOS and an LVvirtual or something, keeping all CentOS stuff (in /home) on the smaller disk.

Thank you for your insight. I'm giving it a try right now.