I'm running DD-WRT on a consumer router that has a usb port. An external drive that I've connected isn't being mounted for some reason. I have confirmed that the external drive works by connecting it to a PC. And I also know that the router's usb port works because I can mount other external drives with it. Since I have the Optware busybox installed, I could use ssh to troubleshoot the issue (more on that below). But I'm not sure where to start.
My router is a F7D3402 Belkin Play running DD-WRT v24-sp2 (mega version), build 17084M with the "NEWD-2" 2.6 kernel. The drive I'm connecting is a ~1tb sata drive, formatted as one large ext3 partition, in a Veris MX-1 enclosure:

DD-WRT's web interface displays no information about the MX-1 drive whether it is directly connected, or connected by way of a usb hub:

Here is the output from dmesg:
usb 2-1: new full speed USB device using ohci_hcd and address 2
usb 2-1: device descriptor read/64, error -62
usb 2-1: device descriptor read/64, error -62
usb 2-1: new full speed USB device using ohci_hcd and address 3
usb 2-1: device descriptor read/64, error -62
usb 2-1: device descriptor read/64, error -62
usb 2-1: new full speed USB device using ohci_hcd and address 4
usb 2-1: device not accepting address 4, error -62
usb 2-1: new full speed USB device using ohci_hcd and address 5
usb 2-1: device not accepting address 5, error -62
I confirmed that the MX-1 drive worked on a Windows PC, where it was identified as a "usb-to-sata bridge." The drive/partition also showed up under Disk Management. The enclosure has it's own power adapter, so it doesn't need to draw USB power from the router.
Using SSH, I have installed a set of packages called Optware on a thumbdrive. The Optware packages I've installed include busybox utilities, which flesh out the tools available to the command line. I use a USB hub to connect both the thumb drive along with MX-1 drive. For instance, I can do fdisk -l, which shows the thumb drive (/dev/sda) and any other connected drives, except the MX-1. This is not normally possible on stock DD-WRT.