While playing with my disc-less environment, booting via gPXE from an iSCSI device, I found out that VirtualBox has direct support for iSCSI while this isn't shown in the GUI. To register an iSCSI device as virtual disc one has to use VBoxManage on the command line:
$ VBoxManage addiscsidisk \
--server iscsi.home.schlueters.de \
--target iqn.1986-03.com.sun:02:f4635770-f010-61be-e8f7-83403206bec5
The result can be checked:
$ VBoxManage list hdds
[...]
UUID: 292b93ef-0fef-41c4-ad9c-700c38d5537e
Parent UUID: base
Format: iSCSI
Location: iscsi.home.schlueters.de|iqn.1986-03.com.sun:02:f4635770-f010-61be-e8f7-83403206bec5
State: created
Type: normal
Usage: test (UUID: 0e9dac71-1a33-42f3-8320-1f157582e931)
Once the disc is registered it can be selected in the GUI (or from command line) while configuring a VM. In my test I once lost the network connection to the iSCSI target, VBox handled that in a safe way by pausing the VM. Quite handy.
