I'm testing the usb server (trial) and it works good in LAN. However the situation changes in the Internet. Disk is mounted slowly (3-10 minutes) and usb disk becomes inaccessible even from host after some writing. Parted shows - Error opening /dev/sdc: No medium found. Only formatting of the disk helps.
I use ubuntu 12.04.3 as server, clients are different - Ubuntu 14.04, Windows 7(x64), Windows XP.
Configuration is default on clients.
I tried both values for TCPNoDelay on the server with the same effect.
Sounds like your network latency (ping times) are high, USB disks are sensitive to this as they read a small amount of data at a time to build a directory tree, not much you can do about it
I tried from different locations and with broadband connections.
What really troubles me is disk failure after writing on it.
If it is result of network latency, it means I can use your server only in LAN.
And I need a solution for sharing usb devices over the Internet.
It is the *latency* that is the issue, not the bandwidth, so it doesnt matter if its "broadband" it needs to have low latency to get good performance for USB disk sharing over the Internet. You should not get any disk issues unless your connection is unstable.
You can share most devices over the internet, e.g printers, scanners, ipads, serial devices etc, but for usb disks you need low latency, e.g really no more than around 5 or 10ms ping times.
Thank you for the answer!