How to setup mysql on tmpfs ?

I am reading a tutorial in french, where the author do it this way :

1.) Create a tmpfs directory :

mkdir /var/tmpfs
mount -t tmpfs -o size=1G tmpfs /var/tmpfs
chown -R mysql:mysql /var/tmpfs/mysql

2.) Add it to fstab :

tmpfs  /var/tmpfs  tmpfs  nodev,nosuid,noexec,noatime,size=1G  0 0

3.) Copy MySQL to tmpfs (is ramfs here is correct?)

service mysql stop
cp -Rfv /var/lib/mysql /var/ramfs/
chown -R mysql:mysql /var/tmpfs/mysql

4.) Edit /etc/my.cnf

datadir /var/tmpfs/mysql

Then restart mysqld and you can optionally add a startup/stop script to backup the ram data to disk...

But I am not sure the above is right : did the writer of this tutorial mistake ramfs for tmpfs here ? He then goes on to use ramfs in the start/stop script, but what ramfs has to do there, isn't it really tmpfs only ?

  • Why would you do this? Commented Jul 11, 2012 at 14:24
  • 2
    To speed up Drupal's SimpleTests, it's really necessary.
    – B2F
    Commented Jul 11, 2012 at 17:49

2 Answers 2


Seems like it was really

cp -Rfv /var/lib/mysql /var/tmpfs/

Working great now.


Before you try doing this: take a look at mysql's "memory" storage engine. I would stick with that rather than having to deal with the many edge cases with e tmpfs.


we were considering the exact same scenario, but luckly ran across the memory engine, and have not had a problem since.

  • Don't you have to change every single database upgrade script in your app to use ENGINE = MEMORY this way? Seems impossible to do if you're running tests differently to live code. The tmpfs solution seems like the only one
    – Richard
    Commented Jan 16, 2017 at 13:17
  • MySQL's "memory" storage engine does not support BLOB/TEXT fields. So for DB's with those, like the one I was working on, MEMORY storage is a non-starter. Commented Jan 28, 2017 at 8:15

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