ah.... for 2.6 systems (rhel5, etc)...
# echo “- - -” > /sys/class/scsi_host/hostH/scan
scans for all devices on channel hostH
# *echo “1” > /sys/class/scsi_host/hostH/device//H:B:T:L//delete deletes device H:B:T:L from channel hostH
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* # echo “/B T L/” > /sys/class/scsi_host/hostH/scan*
adds device B T L to hostH ...
this is for scsi or fiberchannel, AFAIK.
some more stuff about this here -> http://www.linuxjournal.com/article/7321
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