Learned hotswap as well, lately. Mainly when ‘make’ complained about ‘device full’.

Oh, the joy was felt.

cat /proc/scsi/scsi
(figured out adapter ID 4)
Plug in drive
echo “scsi add-single-device 4 0 2 0″ >/proc/scsi/scsi
(Adapter 4 channel 0 device 2 (third bay, so 0 1 … 2 is the new drive I assumed, and I was right)
fdisk /dev/sdc
mke2fs -j /dev/sdc1
mount /dev/sdc1 /mnt
mv /var/www/* (website files, and where the largest amount of space was being used) /mnt
umount /mnt
edit /etc/fstab
mount /var/www

Not bad for 10 minutes figuring and doing. Haven’t tried taking one out that way, though. May have to mock up a simple perl script for it.