USB 2.0 Drives

[ds2ktj]

First off I would like to say that everyone who has put effort into this site has done a great job. I have gathered a ton of information. I was looking to use a USB 2.0 external drive, not to expand the capacity of my tivo, but to simply move streams over to a PC. Does anyone know if a USB 2.0 drive can be mounted under the kernel that is running on a Tivo or DirecTivo that has had the hacks for networking installed? I fugure this nice speedy 480Mbps connection to the drive would be hella faster than the 100 Mbps network dongle for moving data (for the sake of moving data and burning it to a DVD.

Can anyone tell me if this is supported by the kernel? It would seem silly that it owuldn't be - heck Tivo would have a second market if you could plug a USB 2.0 drive in.

[ds2ktj]

Wow! I thought this would be a really easy one. Is there no "removable media" support compiled into the kernel (perhaps not if USB2.0 isnt there).

Anyone have an idea how feasable it would me. It would seem that a MASS STORAGE driver would be easier than a network driver.

[PlainBill]

Wow! I thought this would be a really easy one. Is there no "removable media" support compiled into the kernel (perhaps not if USB2.0 isnt there).

Anyone have an idea how feasable it would me. It would seem that a MASS STORAGE driver would be easier than a network driver.

Try this thread. (http://www.dealdatabase.com/forum/showthread.php?t=24626)

However, I'm not sure how useful this would be.

PlainBill

[Jamie]

Try this thread. (http://www.dealdatabase.com/forum/showthread.php?t=24626)

However, I'm not sure how useful this would be.
Also, check out the usb 2.4.27 backport package (http://www.dealdatabase.com/forum/showthread.php?t=38167), which includes the necessary kernel modules.

I could never get my usb2 drive enclosure to work reliably on the tivo. It appeared to work, but the tivo would hang under heavy disk load, so I gave up.

The best extraction rates I've had have been through a usb2 host-to-host cable to a linux pc: ~7MB/sec.

[ds2ktj]

Also, check out the usb 2.4.27 backport package (http://www.dealdatabase.com/forum/showthread.php?t=38167), which includes the necessary kernel modules.

I could never get my usb2 drive enclosure to work reliably on the tivo. It appeared to work, but the tivo would hang under heavy disk load, so I gave up.

The best extraction rates I've had have been through a usb2 host-to-host cable to a linux pc: ~7MB/sec.


Thanks for the info. It's a start. Once I get my tivo hacked (time...time...time...) I'll look into it (I did a lot of linux programming back in the day when 386s rulled the earth :)). Any reason why the USB 2.0 doesn't appear to go full speed with FastEthernet (or is it just driver/hardware quality?).

[Jamie]

Any reason why the USB 2.0 doesn't appear to go full speed with FastEthernet (or is it just driver/hardware quality?).It's totally cpu bound, as far as I can tell. Even loopback tests through localhost max out at about 60Mbps. Seems that pushing packets through the tcp/ip stack is at least part of the bottleneck. A larger MTU helps by reducing the number of packets and hence some of the overhead. That seems to be why the host-to-host cables do better: you can bump the MTU up by a factor of 10.

Might be interesting at some point to use an instrumented tcp/ip stack to see where the time is really being spent.

[ds2ktj]

Also one of the reasons why I wanted to see how well a USB2.0 drive would do. No TCP/IP stack maybe speed up transfers using cp instead of TCP/IP. If TCP/IP can run on my blackberry without a problem maybe the problem lies in the USB stack (perhaps even intentionally).

[Jamie]

Also one of the reasons why I wanted to see how well a USB2.0 drive would do. No TCP/IP stack maybe speed up transfers using cp instead of TCP/IP. If TCP/IP can run on my blackberry without a problem maybe the problem lies in the USB stack (perhaps even intentionally).It's not just a USB issue if the bottleneck also happens with localhost. What kind of bandwidth can you get through TCP/IP with your blackberry? Can it really do better than a Tivo?

[ds2ktj]

It's not just a USB issue if the bottleneck also happens with localhost. What kind of bandwidth can you get through TCP/IP with your blackberry? Can it really do better than a Tivo?


True (blackberry isn't a real high-bandwidth device..the radio network it to blame for that mainly. Yes it would appear there are limitations in the TCP/IP stack since loopback caps out a 60 MBps (Did the TIVO guys add the TCP stack or did the community - sounds like it's there from TIVO).

However a USB removable disk drive doesnt use a TCP/IP stack. Perhaps some low level drivers are to blame. Perhaps the hardware was never designed to run at the full speed specification. I'll have to probe deeper and look. I appreciate your pointers and information. Thanks for the help!

:)