Useful to identify disks present before/after a rescan of LUNs:-

for x in `ls -1 /dev/sd*`; do echo -n "$x:"; sudo /sbin/scsi_id -g $x; done > file.txt

The output is then in the format:-

/dev/sdt:360a9800044316f6f543f4646506b334d

Capture output before/after rescan of SCSI bus then use something like this to reveal the newly added LUNs (SCSI IDs):-

sdiff prescan.txt postscan.txt | grep ">"  | awk '{ print $2 }' | cut -d":" -f2 | sort -n | uniq