We are looking at temporarily mounting an external hard disk on USB to an ESX1 v4 server from VMware. In /var/log/messages, we see the messages of the device being connected, but we cannot figure out the actual name of the device (/dev/???) to actually mount so we can retrieve the files ?
This is possible to do but no simple task unless you have a server that supports passthrough for USB http://vstorage.wordpress.com/2010/07/15/usb-passthrough-in-vsphere-4-1/
Any easier approach may be to hook the USB up to a Windows Desktop and transfer the files via SCP, after enabling file transfer in the ESXi Console using a program such as http://www.veeam.com/vmware-esxi-fastscp.html
or VSphere, File transfer will work if you don't want to "hack" esxi
Did you add the USB controller AND the USB device to the guest? If not, that's probably the issue.