ST03N - User statistics Report

1.)STAD and/or ST03N will provide you with statistics when users have logged on, what transactions they  ran, how many memory that consumed and so on.


2.) Licensewise (=USMM) you may be after the 'valid from date' or when was the last-logon-date of a specific users. These are informations you can get in USMM and SUIM -> User -> By Logon Date and Password Change.

SGen

1.) Use sgen once you installated new system.
2.) sgen improves the system performance .
3.)By using the SGEN function, the end user will never have to wait for compilation when using the  SAP system
3.)T-code sgen
4.)Select first option & select required component
5.)keep an eye on tablespace , some time it reaches 100%, it may lead to system hang.

Below link will help you to understand the sgen options:

http://help.sap.com/saphelp_sm32/helpdata/en/b1/52583c65399965e10000000a114084/content.htm

Procedure for extending the File system in LINUX:

1.) #vgdisplay ( Identify the proper vg for particular File system )
2.) #PE (Check total number of free PE )
3.) #lvextend -L +1G <file system>
4.) #resize2fs <file system>
5.) df -h

use below link for LVM Baisc idea:
http://www.redhat.com/magazine/009jul05/features/lvm2/