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  • Blog Post: Interpreting Event 153 Errors

    Hello my name is Bob Golding and I would like to share with you a new event that you may see in the system event log.  Event ID 153 is an error associated with the storage subsystem. This event was new in Windows 8 and Windows Server 2012 and was added to Windows 7 and Windows Server 2008 R2 starting...
  • Blog Post: Breaking down the "Cl" in !irp

    Hey there NTDEBUGGERS my name is Randy Monteleone and today we are going to talk about IRPs. In the past we have talked about the IRP structure in passing and showed a field here and there that can be pulled out and used to find answers to stalled IO. I was recently working on a debugger extension and...
  • Blog Post: What Did Storport Do With My I/O?

    In a previous article I showed how to track an I/O request from the filesystem, through the class driver, and to the storage driver.  In that article I concluded with " From this data we can usually assume that the request has been sent to the disk drive and we are waiting for the disk to respond"...
  • Blog Post: Where Did My Disk I/O Go?

    Hello, Mr. Ninja back again.   I recently discovered that although my team often tracks I/O from the file system through to the disk controller, we have never publicly documented the steps required to do this.   This seems like a great opportunity for a blog because most of the structures are...
  • Blog Post: LUN Discovery in a Nutshell

    The way the disk configuration is determined on a Windows system is by a process called “discovery”.   If the disk configuration is ISCSI or Fibre the process is very similar.   I will describe the process on each and you will see they are very similar.   To simplify things this blog will...
  • Blog Post: Understanding Storage Timeouts and Event 129 Errors

    Greetings fellow debuggers, today I will be blogging about Event ID 129 messages.   These warning events are logged to the system event log with the storage adapter (HBA) driver’s name as the source.   Windows’ STORPORT.SYS driver logs this message when it detects that a request has timed out...
  • Blog Post: Using Xperf to investigate slow I/O issues

    Debuggers, Here’s another short video of the type of triage possible with Xperf, this time Bob shows us how to track down a slow I/O issue. Since I/O Manager is instrumented at IoCallDriver and IoCompleteRequest we can often use this information to diagnose a Slow I/O or SAN issue. The steps...
  • Blog Post: The Case of the Low Hanging Filter Driver Fruit

    Written By Jeff Dailey: Not all our cases are crashes, leaks, or high CPU. Sometimes the problems we are faced with are purely a question of why a given application runs slow on a particular version of Windows versus another version of windows. I n other cases an application may just start running...
  • Blog Post: LPC CASE2 – When things are not rosy

    Hello, this is Roy again. In this case we will discuss a scenario where tracing a hung client thread is not possible through LPC data structures and extensions. We would rather use hints from the LPC message sent about the operation that was taking place and other heuristics to arrive at possible reason...
  • Blog Post: Server Hangs with Event ID: 2021 and 2022

    Hi again! This is Tate from the CPR team and I’m going to show you how to debug a Server Service hang and the sometimes dreaded Event ID: 2021 and Event ID: 2022. There is much Voodoo about troubleshooting these two events but never fear, it’s possible to debug quickly given the right approach. ...
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