My router is Belkin F7D3301. It has only two USB ports and I want to add more external drives.
My old setup was x1 MBR 2TB Ext3 and x1 GPT 3TB Ext3 and it has worked flawlessly since I first tried firmware 501. The drives are directly connected to the router without any usb hub. The router has two usb ports. I can read and write just fine.
My new setup includes a usb hub (I have tested with 2 different hubs). I have x1 MBR 2TB Ext3 and x2 GPT 3TB Ext3 (added an extra 3TB drive). I can read from any of the 3 drive without a hitch but it has problem writing to any of the 3TB drive. The 2TB drive doesn't' have any problem. I have already ran e2fs on the drive and it fixes any filesystem inconsistency. (I confirm the router firmware does not create filesystem inconsistency: it was created during usb to usb copying on my PC.) The symptoms of writing/copying are the transfer screen stuck in calculating time and crashing of router. If I do not cancel immediately, it will crash the router then I have to power cycle in order to get it running again. Sometime it doesn't even recover at all after hitting cancel. One out of 20 tries, all 3 drives will read and write as normal; it will work perfectly until the drives go idle. After waking from idle, the write issue kick back in again. The read function always works with no speed reduction throughout the test. I can read from all 3 drives at the same time: running 3 movies one from each drive. I can move files within each drive to different directory but not between drives or to desktop. The issue is intermittent which suspect to me it's bugged. I also noticed if I leave the drive awake for ~10min (router idling, drive idle shutdown kick in around 15min), sometime the write/copying function will work. It is an annoying bug if I need to copy files immediately and I have to wait for it to "warm up". I configured the router only for NAS function. No wifi or routing/gateway are being used.
So far I tried it on firmware tomato-K26USB-1.28.0507MIPSR2Toastman-RT-N-VPN.trx and tomato-K26USB-1.28.0506MIPSR2Toastman-RT-N-VPN.trx Both got the same result.
I have yet to tried the K26 version of the firmware instead of RT-N. I doubt it will make a difference. I will update later tonight.
Update: I download and setup the same configuration with Shibby tomatousb 1.28.0000 MIPSR2-124 K26 USB VPN.
Everything is working flawlessly with 3 drives with usb hub. Write function work instantly upon mounting. It is too bad the read speed on Shibby firmware is slower: it reads 6Mb/s vs 8Mb/s with Toastman firmware. The write is about .5Mb/s slower than Toastman so it's insignificant; I get ~8.5Mb/s with Toastman and ~8.0Mb/s with Shibby firmware.