The hostid on some systems, like Suns, is set in the hardware and uniquely identifies the system. On Linux, the hostid is more of a suggestion than a hard-and-fast rule. It's usually generated at install time, and can be changed with a few lines of python code:
#!/usr/bin/python from struct import pack hostid = pack("I",int("0x210a2500",16)) filename = "/etc/hostid" open(filename,"wb").write(hostid)
You can check this then with the
# hostid 210a2500
Protip: It's always a good idea to back up /etc/hostid first, just in case.
This can help workaround issues with applications like flexlm, that naively assume that hostid is in some way significant on Linux.