I would have made the same post as usconservative did, although not so eloquently. LOL The only thing I would have changed is I would substitute VirtualBox for VMWare. And it would be for no other reason than I’ve used it for several years, I’m comfortable it, it’s reliable, and after Sun bought it, it became flush with new features and options.
usconservative, a most excellent response, btw.
Also, take a peek at http://virtualboximages.com and http://virtualboximages.com/ovfappliances and, http://open-ovf.sourceforge.net. These offer free images and appliances that operate across the VM range, as long as you use .vdi’s and .ovf’s.
They have pre-built .vdi’s for Ubuntu and many other open source OS’s as well as applications. There are also tutorials listed on the Free vdi page itself, http://virtualboximages.com/Free.VirtualBox.vdi.Downloads .
As far as the question on having two disks and a RAID array, here is an explanation of the different RAID configurations and what they offer...
* RAID 0 (striped disks) distributes data across multiple disks in a way that gives improved speed at any given instant. If one disk fails, however, all of the data on the array will be lost, as there is neither parity nor mirroring. In this regard, RAID 0 is somewhat of a misnomer, in that RAID 0 is non-redundant. A RAID 0 array requires a minimum of two drives. A RAID 0 configuration can be applied to a single drive provided that the RAID controller is hardware and not software (i.e. OS-based arrays) and allows for such configuration. This allows a single drive to be added to a controller already containing another RAID configuration when the user does not wish to add the additional drive to the existing array. In this case, the controller would be set up as RAID only (as opposed to SCSI only (no RAID)), which requires that each individual drive be a part of some sort of RAID array.
* RAID 1 mirrors the contents of the disks, making a form of 1:1 ratio realtime backup. The contents of each disk in the array are identical to that of every other disk in the array. A RAID 1 array requires a minimum of two drives. RAID 1 mirrors, though during the writing process copy the data identically to both drives, would not be suitable as a permanent backup solution, as RAID technology by design allows for certain failures to take place.
* RAID 3 or 4 (striped disks with dedicated parity) combines three or more disks in a way that protects data against loss of any one disk.Fault tolerance is achieved by adding an extra disk to the array and dedicating it to storing parity information. The storage capacity of the array is reduced by one disk. A RAID 3 or 4 array requires a minimum of three drives: two to hold striped data, and a third drive to hold parity data.
* RAID 5 (striped disks with distributed parity) combines three or more disks in a way that protects data against the loss of any one disk. It is similar to RAID 3 but the parity is not stored on one dedicated drive, instead parity information is interspersed across the drive array. The storage capacity of the array is a function of the number of drives minus the space needed to store parity. The maximum number of drives that can fail in any RAID 5 configuration without losing data is only one. Losing two drives in a RAID 5 array is referred to as a “double fault” and results in data loss.
* RAID 6 (striped disks with dual parity) combines four or more disks in a way that protects data against loss of any two disks.
* RAID 1+0 (or 10) is a mirrored data set (RAID 1) which is then striped (RAID 0), hence the “1+0” name. A RAID 10 array requires a minimum of two drives, but is more commonly implemented with 4 drives to take advantage of speed benefits.
* RAID 0+1 (or 01) is a striped data set (RAID 0) which is then mirrored (RAID 1). A RAID 0+1 array requires a minimum of four drives: two to hold the striped data, plus another two to mirror the first pair.
I use a two disk RAID on one of my laptops. It’s a RAID 1, one drive “mirrors” the other. This has proven to be an effective data loss prevention tool for me, although it’s not foolproof. Another benefit is that there is no loss of performance. In the 6 years I’ve had it, I’ve lost 4 drives, as I used it while mobile in bumpy, dusty, cold, and very hot areas. I change out the bad drive, swap the jumpers on the mirrored one, and insert the new disk, and then initialize it, which copies an image of the other right over, and voila, I’m back in business in about 20 minutes. You don’t need to swap jumpers, I do that to rotate the drives FIFO. You don’t have to put in a new drive, you can keep on working just fine with only one. Any other RAID configuration than 1, will hit your performance.
What usconservative said about making “master” copies, is the best way to go. I always make a copy as soon as I have set up a new vdi or VM with an OS, and then another after I have installed all the software and tweaked it. Although he’s probably smarter than I am with not putting another 60-200 mb worth of A/V and Firewall on it. doh! (I never thought about that)
BTW, he mentioned it, but I want to emphasize it, Windows 7 Pro and Ultimate are able to run MS’s free virtualization software and free Windows XP inside of Win7. And, surprise, it runs pretty darn good, too, not much of a performance hit as I would imagined.
Good luck.
I run the WindowsXP virtual machine on Windows7 as well as VMWare, but not both at the same time. My preference between the two happens to be VMWare, but only because I tend to work from home and want to isolate my work traffic via VPN from my normal internet traffic. That is, I can establish a VPN connection to work and route traffic for my email, fileserver, softphone (voip) traffic to the VPN connection inside the virtual machine, while maintaining a separate internet connection on the physical machine - but still using the same network card. Since each machine (physical and virtual) has their own IP address, I can split the traffic, which I cannot do with Windows7 and the virtual XP that microsoft provides.
Other than that one key difference for me and the way I work, your observation of there being no noticeable difference in speed with Microsoft's virtual XP on Windows 7 is spot on.
I'm going to give VirtualBox another look-see, it's probably been too long since I have.