VM Networking Improvements in Hyper-V in Windows Server 2008 R2

On the What’s New in Windows Server 2008 R2? page you can see one of the improvements for Hyper-V has been improved virtual networking performance, and specifically “offloading” has been extended through to the child partitions for those physical NICs that offer it. I did an in-place upgrade of my home server today, from Windows…


What’s So Special About The Pool?

One of the tools we use to troubleshoot pool memory corruption is the gflags.exe option "special pool", but what exactly does it do? In order to get to this, let’s first look at what pool memory is – specifically looking here at versions of Windows before Vista (as this changed dramatically with the new memory…


Tweaking for Performance (Disks & Volumes)

There are plenty of people that like to tinker with the operating system to “tune” it and hopefully eke out a little more performance (possibly also going into the hardware side to fiddle with the Front Side Bus speeds. timings and voltages). One of the most common bottlenecks in a modern system is the disk,…


Service Packs – Levels vs Installers

Following the question left on the previous blog entry Branching Out, I need to clear something up that may be a little confusing: A Service Pack level and Service Pack installer are different things. A client with Windows Vista installed that reports itself at Service Pack 2 has all of the hotfixes released prior to…


On Bandwidth and Latency

High bandwidth = good. Low latency = good. There is, however, no direct relationship between the two – bandwidth is measured in (multiples of) “bits per second”, whilst latency is measured in milliseconds (the time between a packet being sent and it arriving at the destination). Analogies with IT-related technologies invariably fail, and are most…


Branching Out

Following on from the previous entry regarding hotfix packages and the branches, here is a fictitious product life cycle:     At time T1 the product is released (RTM). After RTM there is a GDR hotfix package “a” released – this package will contain both GDR and LDR versions of the updated binary. Later, LDR hotfix…

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GDR, QFE, LDR… WTH?

Update 2012-04-16: Later related blog entries (as the topic grew in its scope and version numbering/branch identification changed after Windows Server 2003): Branching Out (2009-05-18) – gives a generic overview of the branching mechanism, with examples Service Packs – Levels vs Installers (2009-05-29) – distinguishes between “service pack level” and “service pack installer” for disambiguation…

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Who is more the spool – the spool or the spool who follows the spool?

The Print Spooler service (spoolsv.exe) in Windows is a very simplistic process with an important job, yet due to its nature can often encounter exceptions and be terminated… through no fault of its own, most commonly. As with every other service in Windows, it is started and stopped through the Service Control Manager (SCM) –…


The Ubiquitous Pagefile

Windows works with virtual memory – the sum of physical RAM installed and the current size of the pagefile(s) in use. The Memory Manager is constantly checking that the working sets of the processes on the system, the kernel and paged pool allocations have been recently used – if they have not then they can…


PAE and 3GB

There is a lot of confusion as to the purpose and impact of these BOOT.INI switches for Windows Server – this leads to a number of cases where "insufficient system resources", "Srv event 2019/2020" and even "hung server" are the symptoms presented.   The brief version is this: PAE (Physical Address Extension) allows the OS…