Redis from docker image redis:6.2.5-alpine3.14 can't start "Invalid LZF compressed string"

This means that the RDB database is corrupted. You should stop the container and restore the file from a backup. If you can't restore it, you can rename/move it to have a corrupted backup in case you want to restore it partially, then start the redis container.

If this is happening often, check if AOF (Append Only File) is better for you. You can have both RDB and AOF at the same time. For more details read also Redis persistence demystified.

To check the consistency of the RDB files you can use:

redis-check-dump dump.rdb

See 4.3.1 Verifying snapshots and append-only files for more details.

If you use a cluster, you can recover one of the nodes with:

rladmin recover list  # To see the list of all files to be recovered

rladmin recover all
rladmin recover db <database_id|name>    # To recover only one DB
recover db only_configuration <db_name>  # To recover only the DB config

rladmin status     # To check which DBs were recovered

Also in a cluster it's possible to recover the the DB with:

rladmin cluster recover ....

See: cluster recover documentation