How to attach a virtual hard disk using VBoxManage?
Solution 1:
Pretty old question but here is how I do it:
VBoxManage storageattach my-vm-name \
--storagectl "SATA Controller" \
--device 0 \
--port 0 \
--type hdd \
--medium /path/to/my-new.vdi
This assumes you want to replace the old disk. If you want to want to just add another disk use another port, for example 1 if you have only 1 disk (on port 0). Please note you could also add disks (or cd/dvd images) to "IDE Controller".
Solution 2:
I believe this should do it for a virtual hard drive.
VBoxManage modifyvm winxp-web-dev --hda "/home/vbox/.VirtualBox/HardDisks/my_new_disk.vdi"
(That is how I do it when I create vm's from the console)