If you’re on DELL Linux box, you might want to try to pick out Service tag quickly via console. You can achieve it by entering the following command.
dmidecode -s system-serial-number
From its man pages:
dmidecode is a tool for dumping a computer’s DMI (some say SMBIOS) table contents in a human-readable format. This table contains a description of the system’s hardware components, as well as other useful pieces of information such as serial numbers and BIOS revision. Thanks to this table, you can retrieve this information without having to probe for the actual hardware. While this is a good point in terms of report speed and safeness, this also makes the presented information possibly unreliable.
The DMI table doesn’t only describe what the system is currently made of, it also can report the possible evolutions (such as the fastest supported CPU or the maximal amount of memory supported).
SMBIOS stands for System Management BIOS, while DMI stands for Desktop Management Interface. Both standards are tightly related and developed by the DMTF (Desktop Management Task Force).