What is boot.properties file and how to create

Boot.properties is a file, it containing  weblogic server username and password .
If your server is in production mode then only you have to create manually this boot.properties file.
If your server is in Development then you no need to create this file because server it self create this file while creating Domain.
A boot identity file contains the user credentials for starting and stopping an instance of WebLogic Server. An administration server or managed server can refer to this file for user credentials instead of prompting at the command line to provide them.

To Create boot.properties:
Go to below location
Win :   C:\Oracle\Middleware\user_projects\domains\test_domain\servers\AdminServer\
Linux : Oracle\Middleware\user_projects\domains\test_domain\servers\AdminServer\
1.First you have to create security folder under AdminServer
2.Create boot.properties file under security folder.
3.Open notepad and write the below two lines
username=**********
password=***********
4.Save the file
5.Now your boot.properties file has been ready from next time your server starting it won't ask username and password, internally your server will call boot.properties file .you can find the below info in your log .
<Sep 21, 2014 10:06:35 PM IST> <Notice> <Security> <BEA-090082> <Security initia
lizing using security realm myrealm.>
<Sep 21, 2014 10:06:35 PM IST> <Notice> <Security> <BEA-090083> <Storing boot id
entity in the file: C:\Oracle\Middleware\user_projects\domains\test_domain\serve
rs\MS2\security\boot.properties>
Note:
If your server is in MSI Mode then you have to copy the security folder along with boot.properties and paste in to all your manage servers.