Fix for Windows 10, 11 virtual machine slowness on VirtualBox

I’ve been using Oracle VirtualBox for last many years and ever since I moved to Windows 10, experienced some unexplainable stuttering and lags with Windows 10, 11 virtual machines. I think finally I made a breakthrough for myself. I am not sure whether this approach is helpful for everyone as virtual machines behave differently on different hardware setups. I’ve gone through many VirtualBox forum posts discussing issues with same nature, particularly with NVidia graphic chips/cards & all my boxes have NVidia graphic chips or cards.

My work laptop configuration.

and has one NVMe ssd for the OS and 2TB SSD for data on which I have all my virtual machines. Regardless, with the amount of hardware resources, my Windows 10 virtual machine stuttered, and the experience was horrible, compared to the Windows XP VM that I had. I never had issues with Linux VMs either. I tried almost every trick in the book and always ended with gaining very little.

Couple of weeks back, for one of the Oracle labs exercises I started the Windows 10 VM and for some unknown reasons found the virtual machine was not automatically resizing display. I managed to fix this problem earlier by changing the graphics controller from VBoxSVGA to VBoxVGA, force auto resize & switching graphics controller back to VBoxSVGA. For that exercise I disabled the 3D acceleration, basically landing on a solution unknowingly. I repeated the same exercise and found my Windows 10 virtual machine snappier than ever! To confirm, I switched back to 3D acceleration & managed to reproduce the same choppy, stuttering experience with the same virtual machine once again.

Let us see what happens with we enable 3D acceleration for the graphics controller.

VirtuaBox allows a maximum of 256MB memory for Video & check the below image to see what happens when we enable 3D acceleration.

half of the video memory is consumed by the 3D acceleration! OS like Windows 10, 11 have pretty heavy graphic elements and obviously the limited video memory makes the OS stuttering and lagging whole the way (or this is what I assume from my experiments).

As I mentioned in the beginning, disabling the 3D acceleration works for me on three different machines & different Windows OS virtual machines. Hope this helps few others out there.

How to hide Powershell background window

I’ve changed from Windows batch files to Powershell for almost every other repeated tasks & one of the scripts that I use to connect to our IKEv2 VPN script has a shortcut on my desktop. This script helps me to connect and disconnect from the VPN network just by double clicking the shortcut. You can checkout the script here

I had multiple iterations for the script and kept on deleting and recreating the shortcut and noticed that a black window started appearing when I executed script from the shortcut.

All I could remember was, not changing any settings for the Powershell & couldn’t find a “solution” (that was mere eyesore to my rigid expectations). Interestingly, my semi desktop/server class box didn’t have this “issue”, whenever I executed the script from the shortcut, all I was provided was the “Connected” or “Disconnected” message boxes.

After sometime, I decided to check the shortcut properties on my desktop & noticed that the “Run” option was selected as “Minimized”

Powershell provides many switches & one of the switches is “WindowStyle” that supports Normal, Minimized, Maximized and Hidden styles for the Window. Well, the style “Minimized” just hid the entire window, including the message popups that had prompts.

Quickly I moved to my laptop and changed the Run to “Minimized” and that was it. No more annoying black window behind my script message boxes! No more script outputs shown on the screen. So, if you reached here seeking a how to hide those annoying black windows, give this a try.

Oracle Application R12 12.2 one user cannot logon

Updated on: 28th Feb 2023

Our previous solution to fix “one user cannot” logon was doomed by additional issues sooner than expected. We had to regenerate the jar files using ADADMIN finally to close the issue.


We are using Oracle EBS R12 for last 12 years and recently upgraded to 12.2.10. We hardly had much technical issues with the instance until recent days, then came a real annoyance.

One particular user was unable to logon. Instead of OA_HTML page, he was either getting redirected to logout page or the OA_HTML page keeps on trying to load. One of the workarounds we came across was, resetting his password. Once the password changed, he was taken to setup password page and to regular landing page. Well, this also turned into troublesome as each time his session expired, we were forced to reset his password.

So what went wrong? We had an issue with concurrent manager outputs and logs opening into a blank page recently. This happened after RMAN backup up, that is scheduled and we had to run autoconfig to fix this issue. Although autoconfig fixed that issue, opened issues with user logon, as explained above. We kept on watching the alerts for possible errors and there were none. Anyhow, we decided to do the following as the ONLY one relevant document we were able to find on Oracle support was “Unable To Login With One User On Oracle EBS Application (Doc ID 2480008.1)” and the case described was not our case.

This is what finally worked:

  • Cleared global cache (didn’t fix issues)
  • Shutdown Apps tier
  • Ran autoconfig on database Tier
  • Ran autoconfig on both Run and Patch file systems
  • Restarted Apps tier and the issues were resolved

We really don’t know what happened after the RMAN & we didn’t update/altered the OS (Oracle Linux 7). Well, things could go south once in a while, after all Oracle EBS is such a huge and complex repository!

Oracle | Single listener for multiple versions of database

Environment: Windows OS (Windows 11)

Currently I’ve 2 different versions of Oracle database installed & instances running from my development machine. Oracle 11G R2 (11.20.4) and Oracle 19c (19.14) & yes, we are supported by Oracle. I had 11G installed first & later installed 19c for checking out APEX and ORDS.

As 11G listener was running, I didn’t notice anything problematic until, tried to connect as a specific user. I started getting the error that the listener doesn’t know of the service name.

PS D:\Oracle19c> sqlplus / as sysdba

SQL*Plus: Release - Production on Thu Jan 12 12:45:30 2023

Copyright (c) 1982, 2021, Oracle.  All rights reserved.

Connected to:
Oracle Database 19c Enterprise Edition Release - Production

SQL> quit
Disconnected from Oracle Database 19c Enterprise Edition Release - Production
PS D:\Oracle19c> sqlplus system@SCTCDB

SQL*Plus: Release - Production on Thu Jan 12 12:45:34 2023

Copyright (c) 1982, 2021, Oracle.  All rights reserved.

Enter password:
ORA-12514: TNS:listener does not currently know of service requested in connect

Enter user-name:

I went ahead and using netca registered the 19c service with 11g listener, restarted the listener services and this time instead of complaining about the missing service, connection attempt froze.

After some confusion, I decided to drop the 11g listener services and created a new listener from 19c environment.

Registered both 19c & 11g services using 19c NETCA this time & restarted the listener. I was able to connect to both databases using username/password@servicename syntax this time.

So let us see what went wrong. 11g database was configured for connections from Oracle Developer 6i legacy applications.

This cannot be modified without failing the legacy application. Please refer the below to understand how the authentication works with different versions of databases and what has changed.

Check for the SQLNET.ALLOWED_LOGON_VERSION Parameter Behavior (

As I am not allowed to change 11g environment, the ONLY one way I can use the same listener was to register 11g service with 19c listener. Simple, clean and effective. Hope this helps few out there who is not a certified DBA like me ;)

Linux 8 | Enable desktop icons

I had a colleague, he challenged me 20 years back that “One day Linux will take over”. I don’t see anyone I know using Linux until date. That’s the end of the story.

So, let us see how a default installation of Linux 8 (Oracle Linux 8) looks immediately after installation

That’s it. User must click on the lone “Activities” menu & choose one of the listed. We’ve had a joke doing rounds about driver’s license application from a particular Indian state. That form had 5 names listed and the applicant was asked to select HIS name from the given.

I don’t have to look for another reason to understand why my ex-colleague was wrong whole the way. Instead of adapting to the users experience base that is mostly around Microsoft Windows, Linux is getting further away from normal desktop users. Minimum the Enterprise editions are. I know Ubuntu is far different from the Enterprise distros & this article is not meant for Ubuntu users.

So, let us see how to get few of the desktop icons (Classic as it is called now)

Click on “Activities” that will provide you a search box. Type in “Gnome” and you will see a number of suggested software listing. Select “GNOME Tweaks” & Install it.

Click on Extensions & switch Desktop icons “ON”. The moment you do that, Desktop icons will be visible.

Shame on you for using the old “Classic mode” geeks. Shame on you!

ORA-00800: soft external error, arguments: [Set Priority Failed], [VKTM], [Check traces and OS configuration]

I do loads of labs & after upgrading a cloned instance of EBS R12 (12.2) database 19c (19.14) to 19.16 & started noticing the error “ORA-00800: soft external error, arguments: [Set Priority Failed], [VKTM], [Check traces and OS configuration]” being logged. I tried to figure out what went wrong after the upgrade & after referring dozens of blog posts and Oracle documents, couldn’t fix this error.

Then, I configured this VM for Oracle ORDS & broke the system by applying few updates that overwritten few mandatory packages for Oracle EBS, forcing me to wipe the system and fresh installation of Oracle Linux 7.9

After applying the prerequisites, I brought up the cloned instance once again & decided to go by the book. After the database clone, I didn’t forget to apply “” from $ORACLE_HOME/bin folder as “root” this time.

If you are ever coming across this error, please ensure the folder/file accesses ($ORACLE_HOME/bin) are like the images below. Running “” fixes much of these access rights.


extjob” & “jssu

This should mostly address the VKTM related issues. If not, please proceed with further measures. If interested refer these documents/posts.

ORA-00800: Soft External Error, Arguments: [Set Priority Failed], [VKTM] [Check traces and OS configuration] (Doc ID 2551359.1)

Hope this helps few out there! Merry Christmas and a Happy New Year in advance!

Oracle VirtualBox 7 | Windows guests auto-resize guest display

Host: Windows 11, 22H2, VirtualBox 7.0.4

I have one Windows 10 guest from last many years, upgraded through VirtualBox versions 5, 6. Recently I upgraded VirtualBox to 7. While Windows XP & Oracle Linux guests automatically resized the display on host, Windows 10 guest was adamant. Uninstalling and installing the guest addons didn’t help.

After scavenging through few posts over VirtualBox forums, came across one of them discussing about fixing the resizing issue by choosing “VBoxVGA”, though it was not supported. I decided to give it a try and Windows 10 guest resized the display when I toggled the “Auto-Resize Guest Display” from the view menu.

Then I shutdown the guest, changed the Display back to “VBoxSVGA” & the guest allowed me to resize the display using View menu & subsequent restarts were resizing the guest display as expected. However, there were times when I had to manually adjust the display size. Hope Oracle fixes this issue in coming releases.

Microsoft SQL Server | CREATE FILE encountered operating system error 5(Access is denied.)

You might come across this error when trying to attach an existing MDF file.

TITLE: Microsoft SQL Server Management Studio

Failed to retrieve data for this request. (Microsoft.SqlServer.Management.Sdk.Sfc)

For help, click:


An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)


CREATE FILE encountered operating system error 5(Access is denied.) while attempting to open or create the physical file 'D:\Microsoft SQL Server\MSSQL\Data\AM8K.mdf'. (Microsoft SQL Server, Error: 5123)

For help, click:



Please do the following:

Make sure currently logged in Windows/Domain user has access to the physical folder where the MDF file resides.

Start “Microsoft SQL Server Management Studio” as administrator.

Now, try to attach the MDF file, this should resolve the Access Denied error.

Windows Mobile hotspot | Connected without internet

Update: 7th December 2022

Today I managed to narrow down the issues to Intel driver specific. AX201 Wi-Fi module driver 22.160 and above breaks the mobile hotspot on both Windows 10 & Windows 11. The only possible solution is to rollback to driver version 22.150.x.x & stay there until Intel identifies and fixes this issue. I have opened a thread with Intel and the representative is investigating this issue. If you are interested, follow the thread here

We’ve poor cellular coverage by the datacenter area from the service provider & most of the times I use my work laptop as Mobile hotspot & it did work. Well, minimum until recent days.

I started seeing my mobile phone showing “Connected without internet” once in few minutes times & I had to reconnect which was a recent development. Unfortunately, I couldn’t land upon any relevant solutions after spending almost two working days searching for solutions & executing my own logic with resetting network/Winsock etcetera.

As I use Samsung Galaxy A71 5G Android phone, I thought of giving another attempt by searching for “Galaxy a71 5g connected without internet” & one of the first search results was:

Samsung Galaxy Phones “Connected without Internet”

Here, the vlogger talks about “Randomized MAC” Galaxy phones use when connecting to Wi-Fi networks. Although the vlogger suggests Static IP address & other changes to resolve this issue, I only changed the connection property from “Random MAC” to “Phone MAC” & days long frustrations were over.

I wanted to figure out why all of a sudden this issue started. I remember using the Mobile Hotspot without any issues, had a PowerShell script to start the mobile hotspot startup automatically whenever I am connected to work network for months & couldn’t just give up because I found a solution. Hence, I continued to find more answers.

There were more videos discussing the same issue about Samsung Galaxy phones & subsequently I landed on a Samsung community discussion here

My mobile is paired over Bluetooth to my laptop & it connects every time laptop restarts. One of the initial settings I checked was to ensure Mobile Hotspot was not setup for 2.4GHz, that causes issues for Bluetooth which uses 2.4GHz by default.

In my case, at work I am not connected to Wi-Fi networks & mobile hotspot is configured to share internet from my domain network connection. By default, as the 5GHz is not consumed by Wi-Fi connections, mobile hotspot utilizes that frequency and leaves a notification, asking to switch the frequency if devices fail to connect.

Hence, it could be one of the many elements as discussed in the Samsung community thread. All you need is to try and find out one that suits your situation. Regardless, if it is a Samsung Galaxy phone, the first solution you could try is to setup Phone MAC instead of Randomized MAC for the specific Wi-Fi connection that you have issues with. If that didn’t resolve, try others.

Oracle Linux | “Peer’s certificate issuer has been marked as not trusted by the user.”

Recently I was trying to update one of the Oracle Linux 7 boxes that is used for lab & came across multiple errors.

OCI : Yum Fails with [Errno 14] curl#6 - "Could not resolve host: yum-iad.$ocidomain; Unknown error"
[Errno 14] curl#60 - "Peer's certificate issuer has been marked as not trusted by the user."

I kept on doing almost everything yum was suggesting, disable the repos, cleaning etc. Yes, I did ping both & to “insure” that I was connected to “internet” (I’m still struggling to figure out how the heck I managed to ping these hosts when I was actually unable to connect to Oracle mirrors)

However, after exhausting more than couple of hours, I decided to access the server through VNC & see whether I am missing something, that cannot be done from the command line.

Fired up Firefox & realized, I am not connected to “Internet” in real terms. I couldn’t open any pages and I proceeded with adding the static IP address to exclusion list and that was it.

So, if you ever come across the above mentioned errors, make sure you ARE connected!