How do I configure fixed length columns in EF Core?

Currently (EF Core 1.1.0) you can only specify column type directly: .HasColumnType("char(123)")

Please make sure your DB engine understand this value! It is passed "as is".

Also please note that you should write all required dimension/length/precision values here, because .HasMaxLength() value will be ignored.

Actually, as for Version 2.1 this is implemented as:

entity.Property(e => e.Name).HasMaxLength(X).IsFixedLength();