Thursday, June 28, 2018

AD Query still returns old user name after user name was changed at domain controller


Consider the following scenario:

  1. On the domain member computer, an application calls the LsaLookupSids function to translate a security identifier (SID) to a user name.
  2. The user name has been changed on a domain controller.
  3. In this scenario, the LsaLookupSids function may return the old user name instead of the new user name. This behavior may prevent the application from working correctly.


The local security authority (LSA) caches the mapping between the SID and the user name in a local cache on the domain member computer. The cached user name is not synchronized with domain controllers. The LSA on the domain member computer first queries the local SID cache. If an existing mapping is already in the local SID cache, the LSA returns the cached user name information instead of querying the domain controllers. This behavior is intended to improve performance.

The cache entries do time out, however chances are that recurring queries by applications keep the existing cache entry alive for the maximum lifetime of the cache entry.


To work around this issue, disable the local SID cache on the domain member computer as follows.

  1. In RegEdit, locate HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
  2. Create a new DWORD directly under "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa", name it LsaLookupCacheMaxSize and assign value 0.
  3. Reboot may not be required.

Note The LsaLookupCacheMaxSize registry entry sets the maximum number of cached mappings that can be saved in the local SID cache. The default maximum number is 128. When the LsaLookupCacheMaxSize registry entry is set to 0, the local SID cache is disabled.


Wednesday, June 13, 2018

Steps to add VS solution to Visual Studio Team Services

Steps to add an existing Visual Studio solution to a repository on Visual Studio Team Services (or Team Foundation Server).

  1. Install Git on your PC first.
  2. Create a project with Git as version control on your Visual Studio Team Services website.
  3. Get the URL of the new project after it is created,
  4. Assuming your Visual Studio solution folder is C:\Dev\VS2017_Eval\WebApp1...
  5. Open command line console. Go to "C:\Dev\VS2017_Eval\WebApp1".
  6. Run command: git init
  7. Run command:
    git remote add origin
  8. add ".gitignore" file to the folder. You can download it from github at
  9. Run command: git add .gitignore
  10. Run command: git commit -m ".gitignore file added"
  11. Run command: git add *
  12. Run command: git commit -m "Initial source codes"
  13. Run command: git push -u origin --all

Step 13 can be done in Visual Studio by using Sync and Push in outgoing commit in Visual Studio, too.

Wednesday, May 23, 2018

SharePoint 2013: Include javascript and css in the MasterPage

<!--SPM:<SharePoint:CssRegistration runat="server" ID="CssRegistration1" Name="&#60;% $SPUrl:~sitecollection/Style Library/style.css %&#62;" After="corev15.css"/>-->

<!--SPM:<SharePoint:ScriptLink runat="server" ID="ScriptLink1" Language="javascript" Name="~sitecollection/Style Library/script.js"/>-->

Thursday, May 17, 2018

Sample Databases (AdventureWorks)

Various SQL Server sample databases including the AdventureWorks2012 sample databases are available at this location.

Thursday, May 10, 2018

WinAero - very useful to customize Windows 10 font size, etc

Since the last major Window 10 updates, the old way to customize the icon font size went away. The closest way to make the Windows 10 desktop icon's font size bigger is through using Settings --> Display --> Advanced Custom Scaling. However, this does not yield the desired result, because it could end up increasing the size of fonts as well as icon size and everything else on the screen in proportion.

 I did a quick Google Search and found a utility called WinAero ( This tool allows granular customization of specific items, such as icon font and icon font size. On a 14-inch screen laptop with 1366x768 resolution, being able to use 11-point, semi-bold Segoe UI font makes it really nice to use the laptop again.

Monday, April 9, 2018

CentOS 6 - Set Static IP

In order to set static ip on CentOS 6:

  1. Open ifcfg-Auto_eth0 file at /etc/sysconfig/network-scripts folder
    1. sudo vi /etc/sysconfig/network-scripts/ifcfg-Auto_eth0
      1. The file name could be different. It could be ifcfg_eth0, too.
  2. Change the content to something like below:
    1. TYPE=Ethernet
  3. :wq
  4. Open resolv.conf and check or correct the nameserver
    1. sudo vi /etc/resolv.conf
    2. It should be like the following.
      1. nameserver
      2. nameserver
  5. Restart network
    1. sudo /etc/init.d/network restart

Other admins use /etc/sysconfig/network file to specify the default gateway. They may not specify DNS1 or DNS2 in ifcfg-eth0 or ifcfg-Auto_eth0 file. Instead, only the /etc/sysconfig/network file is used to specify the nameservers. 

Below is another example of setting up static ip on CentOS 6

## Configure eth0
# vi /etc/sysconfig/network-scripts/ifcfg-eth0

NAME="System eth0"

## Configure Default Gateway
# vi /etc/sysconfig/network


## Restart Network Interface

/etc/init.d/network restart

## Configure DNS Server
# vi /etc/resolv.conf

nameserver      # Replace with your nameserver ip
nameserver       # Replace with your nameserver ip

CentOS 6 - Change hostname

To check the host name of CentOS 6,

hostname -f

To change the host name on CentOS 6,
  1. sudo vi /etc/sysconfig/network
    1. Update HOSTNAME=[] to match the FQDN.
    2. For example,
  2. :wq
  3. If necessary, update /etc/hosts file for internal networking. Change the host that is associated with the IP address.
    1. sudo vi /etc/hosts
    2. change the host name as needed.
  4. Run the hostname command to change the hostname on the server. For example,
    1. sudo hostname
  5. Restart network 
    1. sudo /etc/init.d/network restart

CentOS 6 - Add a user to sudoers

Here are steps in adding a user to sudoers in CentOS 6

  1. Log on as root ( or switch to su with root password).
  2. On the command window, do the following.
  3. Enter "visudo". 
  4. vi loads the sudoer file.
  5. Look for %wheel in the sudoer file by entering " /%wheel "
  6. Remove # from the line "#  %wheel  ALL=(ALL)  ALL" to enable the wheel group with same privileges as root.
  7. Save and exit vi via  :wq.
  8. To create a new user:
    1. adduser   [new_user_name]
    2. passwd    [new_user_name]   [password]
  9. Use the usermod command to add the user to the wheel group:
    1. usermod   -aG   wheel   [user_name]
  10. Switch to the non-root user by entering "su  -  [user_name]"
  11. Test by running a command that's allowed for root only.
    For example, /root is generally accessible only by root user. Try listing the content of /root. 
    1. sudo  ls  -al  /root

Friday, March 9, 2018

Git could not pull because there were uncommitted changes

Recently, I could not pull from origin master on my Visual Studio 2017. Git could not pull because there were uncommitted changes. I forgot that every change in my local repo must first be committed before pull.

One easy way to commit uncommited changes and then pull was using command-line on the Visual Studio solution folder as follows.

git add -A
git commit -m "your message"
git fetch origin master
git pull origin master
git push origin master //To push to the git