How to create a large MySQL database for tests

I wanted to create a fairly big MySQL database (~30GB on disk) for tests. I created a 'test' database, and a 'table2' table, with a 'content' field with datatype TEXT. Here's what I run from Bash:

[email protected]:~$ time for i in `seq 1 500000`; \
do echo $i of 500000; \
mysql -u root -D test -e \
"INSERT INTO table2 (content) VALUES ('`cat /var/log/messages | tr -d \'`')"; \

This took a few hours to finish, while creating data at a rate of 100MBytes per minute on my test server. The size of the database was 30GB.

This did the job but it was too slow. The better way to do it, would be to run the above command for far less repetitions, say 100000, to create a smaller table, then copy that table in the same database as many times as required for the entire database to reach the desirable size, like:

create table2 like table;
insert into table2 select * from table;