Re:Chaining USB drives
by andrewflnr on Friday November 25, 2011 @12:26AM
(#3276306)
How would files on different segments be presented to the OS? Would the directories on each disk be merged together into one root directory, would each one get its own directory, or something else? To make the "just pull out the one with the vacation photos on it" use-case work, you would have to be able to see and control which segment a given file is on.
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> Would the directories on each disk be merged together into one root directory, would each one get its own directory, or something else?
Due to the way most modern filesystems (including all filesystems that windows supports) work, the only clean way to implement this is to have each segment appear as a separate drive. The operating system only sees the drive as a block-level device, so the drive doesn't know anything about folders or files. It just sees binary data.
You could implement a virtual block-level device on the device, and read files from that to write to each segment, but that would be a major performace hit, and push the cost up significantly as each segment would need a processor and a few megabytes of ram.
The only other way I can think of would be a custom driver.