Any one please explain me the concepts of SLP in Netbackup.
If please relevant docs.
SLP was introduced in 6.5. The White Paper explains the concepts that are relevant to all versions, including 7.1 and 7.5.
TECH153154 Best practices for using Storage Lifecycle Policies and Auto Image Replication in NetBackup 7.1 is for 7.1 and 7.5.
You can also read up about SLP in chapter 14 of Admin Guide I :
NBU 7.5 Administrator's Guide for UNIX and Linux, Volume I http://www.symantec.com/docs/DOC5157
NBU 7.5 Administrator's Guide for Windows, Volume I http://www.symantec.com/docs/DOC5159
