The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

  • My badges

  • Twitter Updates

  • My Flickr Stream

  • Pages

  • All categories

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 2,856 other followers

Archive for March 14th, 2019

delphi – Why was TDataSource created originally? – Stack Overflow

Posted by jpluimers on 2019/03/14

From a while ago [WayBack] delphi РWhy was TDataSource created originally? РStack Overflow

5down voteaccepted

It is all about decoupling and indirection.

And with TDataSource there are two kinds of them:

  • Decoupling the master detail relations (TDataSource is in the same module as the TDataSets that are being bound; the detail TDataSet references the master TDataSet by pointing its’¬†MasterSource¬†property to the TDataSource that points to the master TDataSet)
  • Decoupling the UI from the business layer (TDataSets are in a DataModule; TDataSource is on the Form/Frame which contains your UI controls, UI controls reference their¬†DataSourceproperty).

Since many components can point to the same DataSource, you can quickly switch which underlying TDataSet they use by just flipping one TDataSource.DataSet property.


Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

ESXi 6.5: change the automatic startup/shutdown of guest VMs

Posted by jpluimers on 2019/03/14

One more article about differences between the old C# Windows vSphere Client and “new” vSphere HTML5 Web Client in¬†ESXi 6.5 and up.

This time about changing the startup/shutdown sequence so automatically power on and power off virtual machines.

In the old C# Windows vSphere Client, this was at the host level in the configuration tab under Virtual Machine Startup/Shutdown. There you click on Properties, then adjust the order by moving them up and down (screenshots and more detailed instructions are at ESX(i) AutoStart virtual machines: how to change the VM startup/shutdown settings (via: VMware Communities)).

In the vSphere HTML5 Web Client, there are two bits for this:

On the server you need to enable AutoStart:

From:  to:

For each VM you have to enable AutoStart, then determine the order

  1. In the left, select the VM
  2. In the right, choose Actions, then Autostart, then Enable:
  3. Enable the columns in the VM overview:
  4. Order 1 means highest; adjust accordingly for each VM:

If after boot you get a “Failed – The operation is not allowed in the current state.“, then your machine still is in maintenance mode.


Related: ESXi 6.5: change the host name in the ‚Äúnew‚ÄĚ vSphere HTML5 Web Client, or using DHCP option 12 ¬ę The Wiert Corner ‚Äď irregular stream of stuff

Posted in ESXi6.5, Power User, Virtualization, VMware, VMware ESXi | Leave a Comment »

7zip / 7za command-line parameters for highest compression

Posted by jpluimers on 2019/03/14

On my systems these so far give the best compression results with 7zip and p7zip 16.02:

-t7z -m0=lzma2:d=1024m -mx=9 -aoa -mfb=64 -md=32m -ms=on

Note the -d=1024m is mentioned on some sites, but is gone around version 16.


If you want to delete the files after archiving, then use the -sdel switch: -sdel (Delete files after including to archive) switch

If -sdel switch is specified, 7-Zip deletes files after including to archive. So it works like moving files to archive., moves txt files from disk’s directory to a.7z archive.


Posted in 7zip, Compression, Power User | 1 Comment »

%d bloggers like this: