如何使用VBoxManage为VirtualBox中的磁盘设置SCSI主机编号？

Nice question! Let’s walk through exactly how to set the SCSI host number for your disks in VirtualBox using VBoxManage—I’ve done this a few times with multi-disk VMs, so I’ll break it down step by step.

1. First, Set Up a SCSI Controller (If You Haven’t Already) #

Since you were using SATA for your existing 30 disks, you’ll need to add a SCSI controller to your CentOS 7.4 VM first. Pick a controller type compatible with CentOS 7.4—LsiLogic is a reliable default, but LsiLogicSAS or BusLogic also work:

VBoxManage storagectl "YourCentOSVMName" --name "SCSI Controller" --add scsi --controller LsiLogic --hostiocache on

• --hostiocache enables host-side IO caching (optional but recommended for better performance with some workloads).

2. Assign a Custom SCSI Host Number to the Controller #

The SCSI host number is tied to the controller itself. To set a custom host number (e.g., 5), use the setextradata command:

VBoxManage setextradata "YourCentOSVMName" "VBoxInternal/Devices/lsi/0/Config/HostNumber" "5"

• Note the lsi segment: this matches the controller type you chose. Swap it for buslogic if you used BusLogic, or lsisas for LsiLogicSAS.
• The 0 is the controller instance number—if you add multiple SCSI controllers, increment this to 1, 2, etc.

3. (Optional) Assign Custom Target IDs to Individual Disks #

If you want to specify exact target IDs for each SCSI disk (instead of letting VirtualBox auto-assign them), you have two options:

Option A: Assign During Disk Attachment #

When creating and attaching a disk, use --port to set the target ID and --device for the LUN (usually 0 for standard disks):

# Create a fixed-size VDI (matching your existing SATA disk configuration)
VBoxManage createmedium disk --filename "scsi-disk-0.vdi" --size 100 --format VDI --variant fixed
# Attach it to SCSI controller port 3 (target ID 3), LUN 0
VBoxManage storageattach "YourCentOSVMName" --storagectl "SCSI Controller" --port 3 --device 0 --type hdd --medium "scsi-disk-0.vdi"

Option B: Override Existing Assignments with setextradata #

If you already attached disks and want to tweak their target IDs later:

VBoxManage setextradata "YourCentOSVMName" "VBoxInternal/Devices/lsi/0/Config/Target3/LUN0/PortNumber" "0"

This maps the disk on SCSI port 0 to target ID 3.

4. Verify Your Configuration #

Before starting the VM, double-check your extra data settings to confirm everything is correct:

VBoxManage getextradata "YourCentOSVMName" enumerate

Once the VM is running, install lsscsi in CentOS to see the host number and target IDs in action:

yum install -y lsscsi
lsscsi

You’ll see output like this, where 5 is your custom host number and 3 is the target ID:

[5:3:0:0]    disk    ATA      VBOX HARDDISK    1.0   /dev/sdb

内容的提问来源于stack exchange，提问作者Will Johnson