Tuesday, August 18, 2015

Erratic mouse movement in VMware Workstation on a second screen

I heavily rely on VMware workstation for running all flavours of OS's (from Linux to older Windows versions, and there might even be a MacOSX for iOS development running somewhere, maybe). After upgrading to Windows 10 on my new laptop (with a 1080p screen compared to the previous device I was using), I noticed that all of my machines were behaving strange, to the point that basically none of them were useful anymore.


  • Mouse pointer "flickers" around the screen, when clicking/dragging, the mouse pointer jumps to the upper left corner.
  • This only happens when VMware Workstation is running on the second screen attached to the computer, not on the native screen.
  • It happens on ALL operating systems, Linux, Windows, and perhaps also on Mac OS X.
Been looking around a bit to found out what was causing this behaviour, and it turns out that it is a generic problem with Workstation itself.


Thank you VMware forums, the solution is to disable "Display scaling on high DPI settings" on the vmware.exe in the C:\Program Files (x86)\VMware\VMware Workstation folder. 

One of those issues that can drive you crazy, have you reinstalling your VM's a dozen of times thinking it is you doing something wrong, etc etc... so hope it helps :).

Friday, February 20, 2015

Removing OneDrive from Windows Explorer in Windows 10 TP

I've been using Windows 10 Technical Preview for a few months already, and installed the latest build 9926 a few days ago. Since I hardly use OneDrive (but instead a combination of... DropBox, Google Drive and my own OwnCloud), I prefer not to have it visibly polluting my Explorer windows.

In Windows 8.1, there was plenty of documentation on what registry keys to modify in order to hide OneDrive from explorer, see for example here. Unfortunately, the class ID for OneDrive changed in Windows 10 -- use the following registry location instead:


As described in the original EightForums article, set the "Attributes" key to f090004d. I've also discovered that in Windows 10 it is not necessary to perform the "64-bit" actions (no similar key exists under the Wow6432Node).

That already visually removes OneDrive. Next up, make sure it doesn't start again by modifying the "OneDrive" application settings. As back in the pre-Windows 8.1 era, OneDrive can again be disabled by rightclicking the OneDrive icon in the notification area, going to settings and disabling...

Finally, don't forget to enable "Save to Computer by default" in the various Office applications to prevent Office of trying to find that OneDrive folder again...

Et voila, at least in this Technical Preview OneDrive can be circumvented this way. No guarantees whether this will still be the case in future TP's or the RTM version of Windows 10 though...

Please note that this does have an impact on functionality, as Microsoft still has big plans to use OneDrive as to share data & settings across the entire Windows 10 platform - read Paul Thurrott's view on it here.

Tuesday, October 30, 2012

Windows 8 DNS resolution issues and IPv6

One small issue that I faced already a few times, is that the Windows TCP/IP stack does not seem to be able to properly resolve a DNS hostname (FQDN) despite that nslookup returns a perfectly fine result. The same system was running fine in the same network under Windows 7.

The solution was to disable IPv6 on the network adapters of the system. This is just another example of strange issues with IPv6 that find their origin in the fact that the IPv6 code is in fact used very intensively throughout the Windows components. That is also the reason why Microsoft recommends against disabling IPv6. Well.. it helped me anyway, and was easier than configuring IPv6 addresses for my DNS server :).

Friday, September 21, 2012

Upgrading Windows 7 Ultimate to Windows 8 Enterprise

Unfortunately, Microsoft does not support performing an in-place upgrade of a Windows 7 Ultimate installation to a Windows 8 Enterprise edition; Windows 7 Ultimate can only be upgraded to Windows 8 Professional (since Windows 8 does not come with an Ultimate edition). True, there might be little added value for a home user in Windows 8 Enterprise, but since it was the only version I had ready on a bootable USB stick, I tried to fool the installer to continue anyway.

This was surprisingly easy. It suffices to modify the "EditionID" and "ProductName" registry keys in the following location:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\Current Version

from "Ultimate" and "Windows 7 Ultimate" to "Enterprise" and "Windows 7 Enterprise" respectively, to let the installation proceed.

Wednesday, December 22, 2010

A note on Western Digital 2001FASS drives

About a year ago, I decided to open my wallet and cough up some serious money for a good NAS solution for my home usage. With an ESX whitebox, a growing number of pictures and other digital parafernalia that I like to (permanently) store, I decided that a standalone NAS solution would be more reliable than relying on a single (now aging) RAID controller in my ESX whitebox. After all, a NAS is "system independent" so it can be accessed from any device, as long as there is a network. A few weeks later, I ordered the Thecus N7700 NAS from eBay, together with three Western Digital Caviar Black 2 TB disks (type: WD2001FASS). In the meantime, I upgraded to 5 disks.

Neglecting some configurational complexities between ESX and the Thecus (see my previous blogpost on ESX's iSCSI implementation changes in 4.1), everything has been running very fine... until yesterday.

At 17:04 yesterday evening, I received a gmail notification from the Thecus NAS (yes, it sends mails through gmail) indicating one of the Caviar Black disks had failed and that my RAID5 array was now degraded. I was a bit surprised and already fearing another "Sea-gate" incident with another series of continuously failing disks (the "gate" prefix being so popular with "cablegate", I decided to introduce another one :) ).

I decided to remove the affected disk and run the Western Digital drive diagnostic tools on it (which took a dreadfully long 4 and a half hours). Sure enough, a Full Drive test revealed that there were some bad sectors on the drive but that they were succesfully remapped to the spare capacity that drives get exactly to compensate for a few bad blocks. Still, the RAID array was degraded and the drive was reported as being failed (even though it seems to be very easily fixable), so I decided to dive a little deeper into what happened in an attempt to discover why this is not automatically fixed by the drive when such a bad block is discovered.

What I found out, seriously pissed me off. Western Digital does support a mechanism to automatically remap bad blocks to the spare capacity on the drive. However, this can take a few moments so the question rises how the drive should communicate with the RAID controller to report that it is currently busy to do some block remapping. Western Digital has a technology which they refer to as TLER - Time Limited Error Recovery to delay the RAID array of marking a drive as failed.

Fantastic! The only problem is that this software feature is disabled in the 2001FASS drives, simply because it is considered a "consumer" drive. The even more expensive (and trust me, I had to use all my tactics to convince my wife to cough up the money for what I consider a really expensive drive) RE or "RAID edition" drives are in fact almost identical to the 2001FASS drives, with the exception that they have the TLER feature enabled.

Basically, this means that the 2001FASS drive is not suitable for RAID arrays. When a drive encounters a bad block, it will immediately marked as failed even though this is not the case. Talking about a serious bummer! Some report that TLER is not needed for Linux (which is basically what the Thecus NAS is, a Linux box) but my experience seems to contradict this slightly.

For me, this is an important reason not to buy Western Digital anymore -- you need to cough up an additional bucket of money for a feature that should be enabled in any drive -- after all, all motherboards today support a basic RAID functionality! Or, if you want to upgrade at a given time from one drive to multiple drives...

Wednesday, November 24, 2010

A note on ESX 4.x and my iSCSI devices

A few weeks ago, I decided to extend my iSCSI NAS (Thecus N7700) from 3x 2TB Western Digital Caviar Black disks to 5x 2TB Western Digital Caviar Black disks.

Trouble has been my companion ever since. I have been experiencing some serious performance issues since the RAID extension, and was fearing that the different firmware versions of the new Caviar Blacks was confusing my NAS system; mixing firmwares in RAID systems does not seem to be a best practice. The symptoms were very simple: from the moment a lot of I/O was generated (think: 160 MB/s write speeds to the NAS), ESX would loose the iSCSI link to the NAS, which was choking on all that traffic with a 100% CPU usage. As you very well know, storage is ESX's Achilles heel, and very shortly after that, the vmkernel logs would be flooding with messages indicating a path failure to the NAS:

0:00:41:06.581 cpu1:4261)NMP: nmp_PathDetermineFailure: SCSI cmd RESERVE failed on path vmhba36:C0:T0:L3, reservation state on device t10.E4143500000000000000000040000000AE70000000000100 is unknown.
0:00:41:06.581 cpu1:4261)ScsiDeviceIO: 1672: Command 0x16 to device "t10.E4143500000000000000000040000000AE70000000000100" failed H:0x2 D:0x0 P:0x0 Possible sense data: 0x0 0x0 0x0.

After a multitude of firmware up- and downgrades on the Thecus N7700 and a lot of conversation with Thecus Support (which by the way I want to thank for their patience with a guy like me working in an unsupported scenario!), I stumbled across some a strange error message that I had not seen before on an ESX host:

0:00:41:06.733 cpu0:4113)FS3: 8496: Long VMFS3 rsv time on 'NASStorage04' (held for 3604 msecs). # R: 1, # W: 1 bytesXfer: 2 sectors

Some googling quickly pointed me to a few interesting threads, which talked about a VMware KB 1002598 discussing performance issues on EMC Clariion systems with iSCSI. It seems that the iSCSI initiator in ESX allows for for delayed ACK's which apparently is important in situations of network congestion. Knowing that the N7700's CPU usage can sometimes peak to 100% and that this can very briefly can lock up the network link on the N7700, I decided to disable the Delayed ACK's, following the procedure in the VMware KB...

Great success! Performance was rock solid again, and I have no longer experienced ESX hangs ever since!

This made me think a bit, and I remember that I first noticed the performance issues a few weeks after upgrading to ESX 4.0 Update 2 -- I suppose some default setting has changed from a vanilla ESX 4.0 (which I was running earlier) to ESX 4.0 Update 2 that seems to disturb the good karma that I had going between my ESX host and N7700 NAS earlier. Let it be known to the world that also the N7700 with firmwares 2.01.09, 3.00.06 and (the ones I tried) also is subject to the iSCSI symptoms described in VMware KB 1002598.

Friday, November 5, 2010

The joy of WSUS

After a rather unpleasant electrical powerspike earlier this week had made some of my harddisks go wierd (crashing my ESX server with an equally unpleasant PSOD), a quick inspection revealed that no real harm was done -- except for one of the dozen RAID arrays that I have decided to do an automatic rebuild (no real issue). That finished after a few hours so I was able to go back to my comfortable sofa and enjoy some more quality prime time TV (lol). At least, so I thought...

A few hours later I discovered that my domain controller had not survived the ESX crash and was very unpleasantly complaining about a corrupted registry. Deciding that a bare metal (or virtual metal) Active Directory disaster recovery was not really necessary on my home network (recreating the three user accounts was less effort ;) ), I decided to reinstall my entire domain controller. About 30 minutes after that decision, I was again running a new AD domain with the users recreated and the most important servers already rejoined to the domain.

So what did I forget to configure in my enthousiasm to just reinstall the entire bunch? Certificate services, DFS namespace, DHCP server, re-ACL of file server, recreation of user profiles and also my own WSUS server (which were all happily running on my domain controller as well -- beat that SBS!).

My own WSUS server I hear you say? Well yes, with the very unpleasant (which you will have noticed already is the word of today) bandwidth limitations we have in Belgium, my ISP decides to punish me with some low-bandwidth connection after transferring more than 80 GB of data. That is quite sufficient but I prefer not spending it on downloading all my Windows updates 14 times (which is about the total number of virtual machines, physical laptops and desktops I have running on a frequent basis).

Given that my WSUS partition was about 120 GB and 98% filled, the doom scenario of seeing my entire data transfer that my ISP allows me for this month being entirely consumed by frikkin' Windows updates after reinstalling WSUS & synchronizing for the first time, slowly started to set in. An entire month of "small band" in this digital age? The horror... the horror...

So I decided to spend a few megabytes of datatransfer of very actively googling whether it is possible to prevent WSUS from downloading all the updates from the internet. After all, the registry corruption of the domain controller had completely borked its functionality, yet the separate partition (and separate VMDK) which was holding the WSUSContent directory was undamaged.

Most fora and blogs I found on recycling WSUSContent when performing a new installation, refer to a TechNet page called "Set Up a Disconnected Network (Import and Export Updates)" , which explains how the WSUSContent can be copied from one server to other -- however, they are always exporting & importing the WSUS database as well; unfortunately this database got lost when I -- again -- enthousiastically wiped the entire corrupted OS VMDK.

So I just decided to have a go and installed WSUS from scratch, and I pointed the WSUSContent directory to the partition which already contained the updates from the old server. Then I did the following:
  • Configured the WSUS server exactly has before (with the same products to update)
  • Performed the first initial synchronization (this took a long time but using the network bandwidth monitoring in the vSphere client I could clearly see that only minimal amounts of data were transferred during this synchronization -- no actual content was downloaded!)
  • Approved all the updates that were previously also approved.
This turns out to work quite nicely; apparently when WSUS detects that the updates are already downloaded to disk, it will recycle the existing content! Hurray for WSUS and for not torturing me with small band for an entire month!!