Configure your sessions in Redis for Magento 1

in Performance

Hypernode plans bigger than Magento Grow, often have enough memory to store the session data in Redis.
This way sessions are stored in-memory, making the shop faster and use less IO than when using MySQL or files as session store.

Install Cm_RedisSession

First install the Redis sessions plugin from Gordon Lesti to enable session storage in Redis:

modman clone

Configure Magento 1 to store your sessions in Redis

To save your sessions for Magento add/change the following settings in your local.xml:

Now flush your cache:

rm -rf /data/web/public/var/cache/* 
redis-cli flushall

Test whether your sessions are stored in Redis

To verify whether your configuration is working properly, first clear your session store:

rm /data/web/public/var/sessions/*

Now open the site in your browser and hit F5 a few times or log in to the admin panel.
If all is well, no additional sessions files should be written to /data/web/var/sessions, but instead to the Redis database:

redis-cli -n 2 keys \*