Stuck at "Checking and verifying site-up status. This may take some time."

[cefege]

I am running 748 html static sites on my server.

After 749 websites hosted. I can not set up any more sites with the command:
ee site create domain.com --alias-domains='www.domain.com'

I get stuck on the following:
Configuring project.
Creating site domain.com.
Copying configuration files.
Starting site's services.
Success: Configuration files copied.
Success: Host entry successfully added.
Checking and verifying site-up status. This may take some time.
..
Let it run for hours, it's not changing.

My server has 128 gm ram, only 48 are used.

Can you please help me out?