Please take your time to answer/comment. no urgency. it would help upcoming sysadmins like me in understanding how things work in real time.

OS: AIX
Middleware: Weblogic/WAS
Database: Oracle DB/IBM DB2
Backup s/w tools: not available as of now (except native OS commands/utilities)

I'm a newbie (jr SA), I knew little about the theoretical information (like commands) from Redbooks etc. But would like to know more from real time experienced professionals.


for instance;

As an AIX Sys Admin, we are supposed to backup AIX LPAR.
Meaning,
OS: rootvg (OS filesystems)
other software: like middleware/db s/w (uservg)
App: Application data (uservg)

* I understand that DB2/Oracle have their own native backup tools. But I am talking in terms of OS System Admin responsibilites.

I feel like, as an OS admin I need to make sure system(all components) is integrated all the time.

Here are my questions

1) How to Backup whole AIX LPAR (it may be App Server or Database server or fileserver) ?

I understand that mksyb(rootvg) and savevg(uservg) commands are available. Please provide your comments/procedure from based on your experience. (like How organizations implement stuff)

2) How to restore both OS and USER VG ?

scenarios
a) How to restore only 1 or 2 system config files (example crontab file) from backup?
b) how can we restore only OS (AIX) from particular time ?
c) how can we restore few application data files ?
d) how to restore App/DB data from last one month ?
e) how we can restore whole LPAR in case of system crash (need to get back to 3 days old state)?


And I believe that, some Oracle DB and WAS installations update OS filesystems. like they have files saved onto /home directory of their user /home/orcldir.

3) How can we make sure that both OS data and APP data are in sync after restore?

*Please answer all above questions by considering below things
A)if I have backup s/w like TSM or Netbackup tools in my environment.
B) another scenario " we do not have any backup s/w tools like TSM/NetBackup etc"

Please provide your comments/procedure (high-level steps) based on your experience.

Thanks in advance.