Got it, use lmutil hostid -vsn.
C:\sybase\SYSAM-2_0\bin>lmutil hostid -vsn
lmutil - Copyright (c) 1989-2005 Macrovision Europe Ltd. and/or Macrovision Corp
oration. All Rights Reserved.
The FLEXlm host ID of this machine is "DISK_SERIAL_NUM=305bf95a"
Next question is should I use 305bf95a as the new host id? or the whole string 'DISK_SERIAL_NUM=305bf95a' as the host id when generating new license file?