Has anyone any experience on running virtual machines on an USB stick?
Today, I have several development servers running in virtual instances on my external eSata 7200rpm 2.5" disk. However, I have been thinking on instead putting my virtual disks on an USB instead. The sizes (I need 30GB+) and prices has come to a point where it seems feasible.
Anyone actually have done some tests? Is it more performant than a mechanical HD? Any other things to consider?
A SSD is not an option at this point.
Running a VM is not much different to using USB for a general filesystem. The same rules apply. You get good seek performance but poor burst writes relative to a HD. Eventually the memory cells on flash ram degrade and you need to replace them.
For my money I think you'll see an overall improvement in speed since OS bootup usually requires reading many small files. I'd make sure your virtual memory file and temp directories are on a real HD though or you'll wear the flash ram unnecessarily.
Another problem you might have is that if you use more than one or two flash pens, your system will have considerable loss of performance for they might share the same bus, depending on your system specs. Although if you use only one or two usb disks, you might pull it off
Not directly an answer to your question, but from a performance, price and disk space perspective using an external 2,5" USB drive (500 GB) could be a valid alternative. You could even buy two (backup/original) and partition them to get maybe 10 Test-OS on there.