Windows Knowledge Base

[AIX]Difference between AIX Maintenance Level(ML), Technology Level(TL) and Service Pack

Maintenance Level : A Maintenance Level (ML) represents the service updates that are necessary to upgrade the base operating system (BOS) or an optional software product to the current release level. Starting in 2006, as part of the new AIX 5L Service Strategy, MLs are replaced by Technology Levels (TLs). They are defined below.

Technology Level : A Technology Level (TL) is the new term for the twice yearly AIX 5L releases, which contain new hardware and software features and service updates. The first TL will be restricted to hardware features and enablement, as well as software service. The second TL will include hardware features and enablement, software service, and new software features.
Installing a TL should be viewed as an "all or nothing" operation, meaning that requisites will be added so that the whole TL is installed, and not allow a TL to be partially installed. You should back up your system prior to installing a TL.

Service Pack : A Service Pack (SP) consists of service-only updates (also known as PTF's) that are released between Technology Levels to be grouped together for easier identification. These fixes address highly pervasive, critical, or security-related issues. Service Packs are provided for the N and N-1 releases (for example, V5.3 and V5.2) on the latest Technology Level for each release (for example, 5300-04 and 5200-08).