virtualbox.org

Hi,

Is there any way to easily convert a Dynamically Allocated Disk file to a Fixed-Size Disk file? (and vice-versa)

I'm trying to increase the speed of boot up and was wondering if this might be the cause of the slow speed.

Matt

Dynamic vs fixed will extremely likely not change the load speed. The data would still be on the host disk and would still need to be read into the guest OS.

To answer your question directly, no there is no way that I know of to change a dynamic to a fixed. You can make a new fixed disk, load the two disks in a guest that has a cloning software ISO as the boot disk, and clone the dynamic's data to the fixed. 'vboxmanage clonemedium' with the '--existing' switch set might do the clone too.

You could also fill the dynamic disk with random data, filling it out to the fixed size. It would remain a dynamic, though.

Lest this be an "XY problem", let's try to figure out why the guest boots slowly:

Start the guest from full power off, not save-state. Run until you see the problem happen, then shut down the guest from within the guest OS if possible. If not possible, close the Virtualbox window for the guest with the Power Off option set.

Please right-click the guest in the main Virtualbox window's guest list, choose Show Log. Save the far left tab's log, zip the log file, and post the zip file, using the forum's Upload Attachment tab.

You can convert a dynamic VDI to a fixed size VDI using VBoxManage, but since the two formats are identical and differ only in when the blocks are allocated, I guarantee you there will be no change in performance. All that will happen is that the host will have less disk space.