Subject: Re: Useability of NFS over USB disks
To: None <>
From: Peter Seebach <>
List: current-users
Date: 09/19/2006 23:15:38
In message <>, Luke Mewburn writes:
>My experience with external USB storage leads me to recommend
>against using it for production use.


>    *	They don't handle errors in a graceful manner; a bad block
>	on the IDE disk can result in the process accessing the block
>	getting stuck in disk wait for a long period of time.

I would replace "can result" with "nearly always results".

>	Fortunately, I can generally recover from lock-ups
>	by disconnecting the USB cable; the kernel detaches the
>	devices and the process exits.

Most often.  Of course, that's not a particularly elegant solution, and
if you're on -current, it'll panic some weeks.

>    *	You can't access the SMART data on the IDE disk, since they
>	present the disk as a fairly "dumb" SCSI disk.


>    *	Performance is generally "OK" for raw throughput (25MiB/s),
>	contrasted with the native (45-60MiB/s).

Yeah.  I'm on USB1, making it even worse.

>I've considered using IEEE1394<->IDE, but the support for that in
>NetBSD isn't production quality.

Tragically, no.  And I really wish it'd get fixed, because I have a real use
for it, but I don't think I have the competence.