Works in one installation, but not in another? =(

[treefiddey]

Hello everyone. I apologize for the vague question, but I need to resolve this.

On my computer there are 2 "instances" of Windows 7 Pro 64-bit, each on its own HDD.
In one of them (an HDD in the modular bay), VirtualBox is installed with Fedora 18 guest and works great.
When I boot into this instance, I create the VDI on the same physical drive as the Windows installation.

In the second instance (on an SSD drive), VirtualBox doesn't work well at all. Fedora just stalls mid-install and I have to shut down the VM.
When I boot into this instance, I create the VDI on the other (modular bay) HDD, because I don't want to use up precious SSD space.
I haven't tried creating the VDI on the SSD yet, because it's not practical for me to do this anyway.

The second instance is a fresh install and the one I want to migrate to.

If anyone has experienced anything similar or can think of something to try, please let me know.
Thanks in advance.

- treefiddey

[mpack]

Post the VM log file for the problem case, post as a .zip. The VM log file is called "VBox.log", and can be found in the "Logs" subfolder of your VM folder.

[treefiddey]

Thanks for looking into this!

Here it is.

[mpack]

The problem VM seems to be having trouble with host I/O caching. You can trying disabling it in the VM settings (Storage).

I'm also concerned that you've allocated 4GB to the VM, out of a total of 5+ GB RAM available to the host. This is likely to lead to instability because 4GB may not be available in one contiguous chunk (it depends what else runs before you get to the VM). I would cut this to 2GB.

[treefiddey]

Thanks, mpack. Disabling the Host IO Cache totally fixed it!

As far as the RAM, I have 8gb (both windows and virtual box acknowledge this) total. I'm not sure why the log states otherwise.

Thank you very much for your help!

EDIT: With further use, the importance of caching became clear. My guest OS now freezes for about 5 seconds randomly, but eventually unlocks. Any advice on getting Host IO Caching to behave well?

[mpack]

As far as the RAM, I have 8gb (both windows and virtual box acknowledge this) total. I'm not sure why the log states otherwise.

The log says that you have 8GB installed, 5+ GB available. E.g. you can't still have your cake after it's been eaten.

EDIT: With further use, the importance of caching became clear. My guest OS now freezes for about 5 seconds randomly, but eventually unlocks. Any advice on getting Host IO Caching to behave well?

Try Googling to find previous discussions on host caching. I don't have the problem myself, I don't recall specifics on what causes it, but if it was me I'd be looking for a rogue host app that is hogging all the disk or CPU bandwidth. Antivirus is a good place to start IMHO. Background backup comes next. Background defrag or indexing etc. The I/O read and write columns of the task list may be useful (you may have to right click to add these columns).

Of course, if you can think of a background app installed on one of your Win7s but not the other then that would also seem a good clue.

[treefiddey]

Ok, I will look into it. Thank you very much, mpack!

[mpack]

You're welcome. Btw, I was amused by your nickname - I understand the reference and it made me smile.