open mysql on os x backup disk image
On a mac, your MySQL installation is located in:

/usr/local/mysql/


This is the folder structure:

$ ls -lah /usr/local/mysql/
total 64
drwxr-xr-x  16 root    wheel   544B Nov 13 15:54 .
drwxrwxr-x  27 root    admin   918B Nov 24 11:42 ..
-rw-r--r--   1 root    wheel    18K Nov 13 15:47 COPYING
-rw-r--r--   1 root    wheel   7.2K Nov 13 15:47 INSTALL-BINARY
-rw-r--r--   1 root    wheel   2.5K Nov 13 15:47 README
drwxr-xr-x  46 root    wheel   1.5K Nov 13 15:54 bin
drwxr-xr-x  18 _mysql  wheel   612B Apr 27 13:37 data
drwxr-xr-x   6 root    wheel   204B Nov 13 15:54 docs
drwxr-xr-x  37 root    wheel   1.2K Nov 13 15:54 include
drwxr-xr-x  12 root    wheel   408B Nov 23 08:58 lib
drwxr-xr-x   5 root    wheel   170B Apr 25 06:48 man
drwxr-xr-x  19 root    wheel   646B Nov 23 08:58 mysql-test
drwxr-xr-x   3 root    wheel   102B Nov 13 15:54 scripts
drwxr-xr-x  32 root    wheel   1.1K Nov 13 15:54 share
drwxr-xr-x  28 root    wheel   952B Nov 13 15:54 sql-bench
drwxr-xr-x  16 root    wheel   544B Nov 13 15:54 support-files


You probably want to copy all of it to your local disk, then install MySQL from a disk image (DMG), backup the installed data folder, copy your backed up data folder contents into /usr/local/mysql/data, permission the folder to mysql, start mysqld and do an mysql_upgrade.

install mysql server from DMG... then...

 sudo mv /usr/local/mysql/data /usr/local/mysql/data_ORIG
 sudo cp /mybackupfolder/mysql/data /usr/local/mysql/data
 sudo chown -Rf mysql:wheel /usr/local/mysql/data
 sudo su -
 nohup /usr/local/mysql/bin/mysqld_safe &amp;
 exit
 /usr/local/mysql/bin/mysql_upgrade -u root -p
 # read output


*Note: if you have a my.cnf, mv it to /etc/my.cnf.ORIG before you start mysqld.