BSOD KMODE_EXCEPTION_NOT_HANDLED and server slows to a crawl

donathon · Aug 21, 2019

Hi All,

We are facing a very difficult situation here. We have gotten many vendors including Microsoft in but has not found a solution yet. We have a Windows 2012 cluster server some big file shares. Every day the server would either hit a blue screen or slow to a crawl. We migrated to Windows 2016 cluster and the BSOD went away although we did have 1 or 2 every now and then but we are not getting any more slowness reports. The key thing that we suspect is within the shares, we used symbolic links to point some of the folders to another share within the same server. We are wondering if this could be the cause of the slowness and the crash?

philc43 · Aug 22, 2019

There are no recent crash dumps but the ones from the end of July show that you have Driver Verifier enabled. This will cause your system to slow down. Is it still enabled? If so turn it off and see if the system improves.

If you do not know how to turn it off have a read through the following tutorial which will tell you more about the reasons why you would use it and it shows various ways of disabling it.
Driver Verifier - BSOD related - Windows 10, 8.1, 8, 7 + Vista

donathon · Aug 22, 2019

Hi,

If there is no blue screen but the server slows to a crawl and the only way to recover from the slowness is to disconnect the disk from the server, what could be the cause? It seems like something is holding on to the mounted disk volume refusing to let go until there is some sort of time out. Once the disk is gone from the Disk Management, the server recovers back to normal speed. The C:\ is local so a slow LUN is definitely not the cause here. I have disabled the verifier in the meantime.

philc43 · Aug 23, 2019

Have you analysed what is happening on the disk during the slow period? Is there any defragmentation going on?

Maybe try Windows Performance Analyser?

donathon · Aug 23, 2019

The disk queue length all looks fine. There is no contention on the disks. Even if there is, there is no reason why it would cause the server to be slow. Even the mouse moving is slow.

philc43 · Aug 23, 2019

What about memory or page file issues? Have you tried changing the page file location?

An Error showing up in the event log need attention:

Code:

2019-08-20T03:39:04.479  Volume F: (\Device\HarddiskVolume7) needs to be taken offline to perform a Full Chkdsk.  Please run "CHKDSK /F" locally via the command line, or run "REPAIR-VOLUME <drive:>" locally or remotely via PowerShell.

donathon · Aug 23, 2019

It is already moved to a different drive so it should not be a big problem. I was monitoring the counter SMB Server Session \ Total File Open. It kept on going up. It reached to 19 million before it suddenly drop to zero after we dismounted the drive. Could it be cause of the slowness?

MichaelB · Aug 31, 2019

donathon said:
It is already moved to a different drive so it should not be a big problem. I was monitoring the counter SMB Server Session \ Total File Open. It kept on going up. It reached to 19 million before it suddenly drop to zero after we dismounted the drive. Could it be cause of the slowness?

did you monitor your network?
may be also some intrusion, server is busy handling smb-connections.
SMB and the return of the worm

donathon · Sep 2, 2019

Hi, does not seems to be network related. It looks more like a technical limit of some sort...

MichaelB · Sep 2, 2019

So start over here to see if you can impact the Limit
Für die leistungsoptimierung für SMB-Dateiserver

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BSOD KMODE_EXCEPTION_NOT_HANDLED and server slows to a crawl

donathon

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philc43

BSOD Forum Moderator, BSOD Academy Instructor, BSOD Kernel Dump Expert

donathon

Well-known member

philc43

BSOD Forum Moderator, BSOD Academy Instructor, BSOD Kernel Dump Expert

donathon

Well-known member

philc43

BSOD Forum Moderator, BSOD Academy Instructor, BSOD Kernel Dump Expert

donathon

Well-known member

MichaelB

Sysnative Staff, BSOD Kernel Dump Senior Analyst

donathon

Well-known member

MichaelB

Sysnative Staff, BSOD Kernel Dump Senior Analyst