Features of the Windows Server 2008 Product Line

A number of core changes were made to Windows Server 2008. Many were part of Windows Vista kernel changes (Windows Server 2008 and Vista have essentially the same kernel), but some are Windows Server 2008–specific. Not all kernel features in Vista are present in Windows Server 2008. Many of the more multimedia and lower-end performance improvements are not available in Windows Server 2008.

■ One version of the kernel exists for 64-bit Windows Server 2008 (in both checked and nonchecked versions). 32-bit Windows also has a Physical Address Extension (PAE) version. There are no single-core versus multicore versions of the kernel anymore because most systems now have multiple cores. The extra work to lock multicore systems is such a small overhead on today’s systems that it is of negligible benefit to remove for single-core systems.

■ Windows Hardware Error Architecture (WHEA) provides a simplified experience and crash-handling process for sending crash information to Microsoft. If the cause is known, information about a cause or resolution is communicated to the system administrator.

■ Internal changes were made to how threads are allocated CPU cycles, so threads now get a fairer share of the processor. Other changes were made in how I/O completion is handled. The kernel is now kinder and gives better performance.

■ Kernel Transaction Manager allows file and Registry changes to be placed in a transaction and atomically committed or rolled back as one unit. These transactions cross processes and even systems.

System protection and Windows Update use this to safely apply updates. If the system crashes in the middle of an update, the transaction is not applied until the update is complete, so no changes have taken place.

■ Dynamic addition/removal and changing of processors and memory— known as dynamic partitioning. Error-correcting code (ECC) memory notifies of pending failure and Windows Server 2008 moves information off the failing memory so that it can be replaced. Hot processor addition is great; however, by default, applications have to request to be able to “see” additional processors. This is to protect the application because some applications perform certain preparation at startup based on the number of processors. If another core was suddenly visible and the application did not set up structures for it, the application crashes.

■ Self-healing NTFS, facilitated by an NTFS worker thread that runs in the background performing chkdsk-type corrections when it detects a corrupt file or folder in NTFS. The administrator gets balloon tooltip notification that the system is performing a repair and when the repair finishes. This avoids many manual chkdsk executions.

■ SMB 2.0 offers huge performance increases over the old SMB. Let’s take a high-level look at the activities performed by a client and examine how Windows Server 2008 addresses them. The rest of the book goes into detail about the features.