In WT-4415 I wanted to try out direct_io=[data] with a buffer alignment of 32k. In order to do this, one must add buffer_alignment=32k to the connection configuration and also allocation_size=32k to the table creation configuration.

However, this does not work because it will fail in wiredtiger_open when attempting to create the metadata file internally WiredTiger.wt (and likely creating the lookaside table as well, but I didn't get that far).

AFAICT, there are no tests that use a non-default buffer alignment.