This article is meant to be a give more insight in what a Volume Serial is and what it means on different Operating Systems, because a Volume Serial is not always a Volume Serial.
But what exactly is the volume serial?
A volume Serial is a serial number created upon the moment a disk partition was formatted using the current date and time.
A disk can have multiple partitions and therefor have multiple Volume Serials. The SecondLife viewers will pick one of them and use it as a identifier for your computer and your alts.
What is my volume serial in Windows?
On Windows the Volume Serial of the Operating System is picked which is usually Drive C:
Open cmd and type:
What is my volume serial in Linux?
Linux does not use drive letters to identify the operating system. The algorithm used to identify which volume serial will be used as identifier is therefor different.
The Linux algorithm selects the longest volume UUID’s in the /dev/disk/by-uuid directory, followed by the alphabetically highest volume UUID.
This approach seems to suggest that a USB stick with a alphabetically higher UUID can potentially act as a volume serial spoofer on legitimate viewers (which is interesting)
To view which volume serial is used paste this in the terminal (Only tested on Ubuntu 20.04):
lsblk -f | grep `sudo ls /dev/disk/by-uuid | perl -e 'print sort length($a) <=> length($b) <>' | tail -n 1`
What is my volume serial in macOS?
In macOS the algorithm does not use Volume Serials, but they use the hardcoded device serial number.
ioreg -l | grep IOPlatformSerialNumber
When is the volume serial transmitted?
The volume serial is send as a md5 hash upon login and every 300 seconds (5 min) via viewerstats