Can 2 different versions of MySQL be run side by side? I have Debian 10 installed and have an instance of MySQL 8 running.

I'd like to install 5.7 to try and bring up the database of a machine that failed, where I have the data directory fully intact, so I can inspect it and save the schemas, data, triggers, functions and stored procedures.

Does this question make sense?
The database I wanted to restore was actually MySQL 5.5.29. OH NO!
Based on the suggestion of @mustaccio, I set up a docker container to
run the MySQL 5.5 instance.

bazzani has a MySQL 5.5 docker image builder so I used that
The last step, to use the backed up MySQl instance files with the docker image
was completed with:

docker run --name=mysql55 -d -v ~/mysql:/var/lib/mysql mysql5.5


Find the IPAddress of MySQL in the container:

docker inspect mysql55 | grep -i ipaddress


After that it was easy to access the database and properly dump the data, schema and triggers and grants:


Grants

mysql -u user -ppassword --skip-column-names -A -e"SELECT CONCAT('SHOW GRANTS FOR ',QUOTE(user),'@',QUOTE(host),';') FROM mysql.user WHERE user&lt;&gt;''" | mysql -u user -ppassword --skip-column-names -A | sed 's/$/;/g' &gt; MySQLUserGrants.sql
Routines

mysqldump --column-statistics=0 -h 172.17.0.2 -u user -ppassword  --no-data --no-create-info --routines ${DB} &gt; ${DB}-routines.sql
Schema and Triggers

mysqldump --column-statistics=0 -h 172.17.0.2 -u user -ppassword --no-data --triggers ${DB} &gt; ${DB}-schema-triggers.sql
Data

mysqldump --column-statistics=0 -h 172.17.0.2 -u user -ppassword --no-create-info --skip-triggers --no-create-db --compact ${DB} &gt; ${DB}-data-only.sql


This whole solution was important as 12 months of research in multiple databases had been poorly backed up using mysqldump this way:

mysqldump --force --opt --user=$MYSQL_USER -p$MYSQL_PASSWORD --databases $db


This command dumps everything in a single file, which is not workable, so all current backups mostly useless. Fortunately the old drive is solid though the machine is dead.