Quoting Andrew Greig (pushin.linux@gmail.com):
I have a SCSI scanner Epson GT7000, which I love, but occasionally in the past I may have turned it off, and as a consequence it is not detected at boot. In the old days when boot times were quick I would turn it on and reboot, but boot up time is not trivial in my Ubuntu system and so I am inquiring is there a way for the system to discover that the scanner is now turned on. Is there a way for the device to say "hey, I'm here now, let's play". Or for the system to say, "well you weren't here at the start, but we'll let you play"
As the root user, try: echo 1 > /sys/class/scsi_device/device/rescan (Variations on that are covered at https://thornelabs.net/2012/08/22/linux-rescan-scsi-bus.html, which please also see.[1]) There is also a related script rescan-scsi-bus.sh traditionally said to be furnished by something called sg3_utils, which I have not seen.) (Disclaimer #1: The first tip worked long ages ago, but I've not tested it in a long time.) (Disclaimer #2: I am in a very different time zone where I am up a bit past my bed time, ergo not ideally situated to fact-check before trying to help. Sorry, good sir.) [1] Web-search on 'scsi rescan linux' if not yet getting anywhere. Could work. -- Cheers, "He who laughs last, lasts." Rick Moen -- Leo Rosten rick@linuxmafia.com McQ! (4x80)