To disable USB device in Linux(RHEL5) system...

apply one of the following methods

1. # mv /lib/modules/2.6.18-128.el5/kernel/drivers/usb/storage/usb-storage.ko /opt/

2. # echo "blacklist usb_storage" >> /etc/modprobe.d/blacklist

3. # vim /etc/grub.conf

write in kernel parameters "nousb"

kernel /vmlinuz-2.6.18-128.el5 ro root=LABEL=/ rhgb quiet nousb

To ping a group of computers -

fping -g 192.168.0.1 192.168.0.10 2>/dev/null

Download the fping utility from the following link -

http://dag.wieers.com/rpm/packages/fping/fping-2.4-1.b2.2.el5.rf.i386.rpm