9 Advanced topics
to the VBoxSDL main thread (first entry in the ps list). For example, when switching away to another VT and saving the virtual machine from this terminal, the following sequence can be used to make sure the VM is not saved with stuck modifiers:
kill
VBoxManage controlvm "Windows 2000" savestate
9.9 Launching more than 120 VMs on Solaris hosts
Solaris hosts have a fixed number of IPC semaphores IDs per process preventing users from starting more than 120 VMs. While trying to launch more VMs you would be shown a “Cannot create IPC semaphore” error.
In order to run more VMs, you will need to bump the semaphore ID limit of the VBoxSVC process. Execute as root the prctl command as shown below. The process ID of VBoxSVC can be obtained using the ps list command.
prctl
9.10 Using serial ports
Starting with version 1.4, VirtualBox provided support for virtual serial ports, which, at the time, was rather complicated to set up with a sequence of VBoxManage setextradata statements. Since version 1.5, that way of setting up serial ports is no longer necessary and deprecated. To set up virtual serial ports, use the methods now described in chapter 3.9, Serial ports, page 55.
Note: For backwards compatibility, the old setextradata statements, whose description is retained below from the old version of the manual, take precedence over the new way of configuring serial ports. As a result, if config- uring serial ports the new way doesn’t work, make sure the VM in question does not have old configuration data such as below still active.
The old sequence of configuring a serial port used the following 6 commands:
VBoxManage setextradata "YourVM" "VBoxInternal/Devices/serial/0/Config/IRQ" 4
VBoxManage setextradata "YourVM" "VBoxInternal/Devices/serial/0/Config/IOBase" 0x3f8
VBoxManage setextradata "YourVM" "VBoxInternal/Devices/serial/0/LUN#0/Driver" Char
VBoxManage setextradata "YourVM" "VBoxInternal/Devices/serial/0/LUN#0/AttachedDriver/Driver" NamedPipe
VBoxManage setextradata "YourVM" "VBoxInternal/Devices/serial/0/LUN#0/AttachedDriver/Config/Location" "\\.\pipe\vboxCOM1"
VBoxManage setextradata "YourVM" "VBoxInternal/Devices/serial/0/LUN#0/AttachedDriver/Config/IsServer" 1
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