Increasing the LOG file size

I was doing some research into VLF and was trying increasing the LOG files with different sizes.

I came across with wired situation where when ever I crease the log size by 4GB, it increases with no time, but I go with less size it takes few or more seconds.

Here is the test.

Simply I created the database with 1 GB log file.

Then I expand the log file with 1-7 GBs and every time I re-create the database.

Here are the results.

It is almost a straight line except for 4 GB.

Let us see the physical log growth at each instances.

So surely there is something wrong when you are incrementing by 4GB. When searching I found the blog post from Paul where he confirms that this is a BUG.

I confirmed that this is resolved in SQL Server 2012.