Total storage space and Serial number

Hi,

Could you please tell me the commands to find Total storage space and Serial number of Linux server.

OS -- Red Hat Enterprise Linux Server release 6.6 (Santiago)
This is 2 node cluster.

Regards,
Maddy

You can learn anything you need about your disk with the following commands:

df -h
cat /proc/partitions
lsblk
fdisk -l
hdparm

I do not know what you are referring to by "serial number" but I do not doubt whatever it is you might find it using:

dmidecode

Some of them requires superuser privileges.