[CentOS] Rescan /dev/sd* without reboot?

Joseph L. Casale wrote:
>> This is an old way of doing it but it's worked fine for me over the
>> years.
>>     
>
> I think the new way is documented here:
> http://www.linuxjournal.com/article/7321
>   

i've had very good luck with

echo "- - -" > /sys/class/scsi_host/host?/scan

replacing ? with the proper scsi/fiberchannel host channel #

done this on online systems with minimal impact to other in-use drives.