Reply to: Tossing a VM between machines

[TheFaQQer]

I was thinking that if you had your dev-PC running as a VM, you could simply throw this single VM file between your desktop and laptop when you have to travel rather than muck about with SVN, Dropbox, yada yada.

Is this feasible - is a VM image a single entirely self-contained file?
Are there even any tools to sync a VM image between multiple machines so you don't have to copy the whole multi-Gb file each time?

I do it with VMWare - copy the files onto a USB3 HDD for using on my laptop, then when I'm back I copy them back onto the desktop machine.

Works between Windows and Linux as well with no issues - been doing it for years, as I have a Windows XP virtual machine for development work but prefer to use Linux for my desktop machine.

[d000hg]

How about a DaaS from someone like Desktone?

If that was aimed at me, no good because the point of a laptop is you can work on the move, and wi-fi good enough for RDP cannot be relied on even where wi-fi is provided.

[stek]

Tossing a VM between machines

How about clustering? One node on dev-pc, tother on Lappy, shared disks fail over as required?

[SimonMac]

If you have an MSDN licence you can do something with Azure if you really want to go down that route

[rob s]

How about a DaaS from someone like Desktone?

[VectraMan]

Doesn't your second point emphasis why your first suggestion is impracticable. By having the hard disk separate you can mount it everywhere and change the hardware specifications at will (and I do frequently when moving machines around).

No reason why it couldn't work both ways. I'd suggest changing the virtual hardware is rare; I can't really think of why you'd do that frequently, whereas being able to move the virtual machine to different physical hardware is part of the raison d'être of VMs. That's a lot easier if it's based on a single file.

It'd be even better if the single file was an executable. Then you'd never even have to worry about installing VirtualBox or whatever. Just copy the file, and run it, et voila: a VM.

[Sysman]

Completely practical, especially if you have an SSD in there. I actually bought my first SSD for exactly this purpose, though I also bought an eSATA express card the VMs ran fine over USB2. The only minor annoyance is that you won't have TRIM support.

Yep. It's a good idea to keep your VMs off the system disk anyway. Even USB2 speeds are better than having everything thrashing the system disk, especially if you are doing I/O intensive stuff in either the host or the VM, or both.

[eek]

Blimey...how many machines do you use / burn through / buy?

But yes, I've switched VMs between hosts before, it works fairly well - and you've already identified that deliverables are going into a repository.

In my case I meant the virtual machine settings (CPUs, cores, memory).

Oh and on aws I can change machines fairly frequently.

[rob s]

Blimey...how many machines do you use / burn through / buy?

But yes, I've switched VMs between hosts before, it works fairly well - and you've already identified that deliverables are going into a repository.

[eek]

I've always thought this is a bit of a flaw with Virtual Box and others. It would be dead easy (and make little difference to the file size) to write the details of the VM to the Virtual Hard disk file. In that way you could easily just start up any VM by browsing to its VHD.


BTW .vbox files hosted on Windows aren't compatible with Linux, and vice-versa. I found this out the hard way whilst trying to dual boot a machine with both. I thought I'd just be able to run the same VMs regardless of the host OS, but no I had to set them up seperately.

Doesn't your second point emphasis why your first suggestion is impracticable. By having the hard disk separate you can mount it everywhere and change the hardware specifications at will (and I do frequently when moving machines around).

[VectraMan]

I've always thought this is a bit of a flaw with Virtual Box and others. It would be dead easy (and make little difference to the file size) to write the details of the VM to the Virtual Hard disk file. In that way you could easily just start up any VM by browsing to its VHD.

But no, it treats the hard disk as a seperate thing to the VM, which obviously has its uses but most the time you probably want a single machine with a single hard disk.

However there's no reason why you can't just set up identical VMs on two different machines, and then just copy the hard disk over. You'd have to be careful to keep all the settings the same, and I don't think it would preserve any snapshots or saved state.

BTW .vbox files hosted on Windows aren't compatible with Linux, and vice-versa. I found this out the hard way whilst trying to dual boot a machine with both. I thought I'd just be able to run the same VMs regardless of the host OS, but no I had to set them up seperately.

[doodab]

I even wondered if one could simply keep the VM on a portable USB drive, then use it on any PC you wanted... but is that impractical with USB2?

Completely practical, especially if you have an SSD in there. I actually bought my first SSD for exactly this purpose, though I also bought an eSATA express card the VMs ran fine over USB2. The only minor annoyance is that you won't have TRIM support.

[d000hg]

I even wondered if one could simply keep the VM on a portable USB drive, then use it on any PC you wanted... but is that impractical with USB2?

[d000hg]

Maybe I misunderstand when you guys talk about syncing the contents. The 'contents' of the VM would not just be things like programming code, but all the installed apps on a typical developer machine. If I got a new laptop, my thinking was this could save having to do any setup other than dumping the VM (or it's HD image) on it and installing the VM client. It could even include the running state of applications if I hibernate/suspend the VM?

Work would still be saved into SVN or other backup solutions, this is more like cloning the whole setup than something I'd do every morning.

[Sysman]

I wouldn't say portable, but you can export the *.vmdk and *.vbox as one *.ova file, but its a one hit thing so not sure how much time you would have if you are regularly swapping between machines.

It's been a while since I bothered with .ova files because I found creating them incredibly slow and they didn't always work.