I'm trying to use an Areca 1200 controller with ESXi 4.1.0.
ESXi is installed onto an USB stick, and boots fine. All hardware is recognized except for the Areca controller.

I've downloaded the latest driver from the Areca site for Vmware, installed the offline package with esxupdate like described in the readme.

After installation and reboot the driver is loaded, but the controller isn't recognized.

~ # esxupdate query --vib-view | grep "arcmsr"
cross_vmware-esx-drivers-scsi-arcmsr_400.1.20.00.15.vmk.110418-1OEM installed 2011-09-28T23:13:38.418653+00:00
~ # esxcfg-scsidevs -a
vmhba0 ata_piix link-n/a sata.vmhba0 (0:0:31.2) Intel Corporation 4 port SATA IDE Controller (ICH9)
vmhba1 ata_piix link-n/a sata.vmhba1 (0:0:31.5) Intel Corporation 2 port SATA IDE Controller (ICH9)
vmhba32 usb-storage link-n/a usb.vmhba32 () USB
vmhba33 ata_piix link-n/a sata.vmhba33 (0:0:31.2) Intel Corporation 4 port SATA IDE Controller (ICH9)
vmhba34 ata_piix link-n/a sata.vmhba34 (0:0:31.5) Intel Corporation 2 port SATA IDE Controller (ICH9)

What is wrong here ?

I also tried with ESXi 5.0, there the card is recognized, but the driver isn't automatically loaded after a reboot.

The controller works fine with Ubuntu 11.04, ...

Thank you.

After you reboot take a look at /var/log/messages. Do you see a section where the driver is loaded and it attempts to claim any devices?

/var/log # cat messages | grep "arcmsr"
Sep 29 20:40:18 vmkernel: 0:00:00:03.044 cpu0:4096)VisorFSTar: 1549: etc/vmware/init/manifests/areca-arcmsr.mf exists already, replacing
Sep 29 20:40:18 vmkernel: 0:00:00:03.044 cpu0:4096)VisorFSTar: 1549: etc/vmware/pciid/arcmsr.xml exists already, replacing