Should I worry about the quality of a USB drive when I install vSphere from USB?
VMware's ESXi hypervisor will install on any storage device, so long as your computer's BIOS can be configured to boot off of the device. This includes any USB key you wish to use, with an important caveat: Not all USB flash drives are made equal. With very few exceptions, USB flash drives are a terrible idea for use with VMware virtualization and a potentially criminally bad idea in your production infrastructure.
Sadly, the fact that VMware and USB flash drives don't mix does not stop any of us -- myself included -- from using USB keys to load VMware hypervisors. Most USB drives are significantly slower than solid state drives (SSDs), and indeed slower than 5,400 RPM hard drives. To load up the hypervisor, this snail's pace doesn't matter all that much, but consumer USB drives' painfully low NAND cells write limits are a real concern.
Several companies -- STEC and Amtron come to mind -- offer industrial flash drives at reasonable prices. These are often single level cell NAND drives. You can spend $30 for a 1 GB USB stick with 100,000 write cycles, more than $1000 for full-bore SSD-class storage in a USB chassis or any amount in between.
If you are going to use USB storage in a production VMware infrastructure, I recommend Amtron flash drives. If you are just looking to carry a hypervisor around in your pocket for periodic access, any old flash drive will do.
This was first published in February 2013