Backing up redis rdb file is simply copy .rdb to your backup location. So, we have to choose any safe destination that we'd like to store the snapshot file (It is usually safer to transfer to a different server or disk). But, let's figure out where the current RDB file is located
cat /etc/redis/redis.conf |grep '^dir '|cut -d' ' -f2
On my box, /var/lib/redis is the directory where the snapshot file is dumped to. Before copying, it is good idea to save the db in background.
Then copy it to somewhere that is safe. (The path /backup/redis is just an illustration of where it could be copied to)
cp /var/lib/redis/dump.rdb /backup/redis/dump.$(date +%Y%m%d%H%M).rdb
That's it. It is simple as that, you don't need to do anything special with your server in order to back up redis rdb. However, restoring Redis snapshot depends on the configured Redis server if it is in the fashion of the AOF (Append Only File) or not. Assuming that the Redis configuration file is at /etc/redis/redis.conf, you could simply check if it is in AOF mode by issueing this command
cat /etc/redis/redis.conf |grep 'appendonly '|cut -d' ' -f2
'yes' means AOF mode is enable. 'no' means AOF mode is disable.
In case it is not AOF mode. ('no'), the process is quite straight forward. First, just stop redis server
Then, remove the current dumb.rdb file
rm -f /var/lib/redis/dump.rdb
And now the snapshot file has gone, therefore we definitely want the backup one back in.
Remember to set it to be owned by redis user/group
chown redis:redis dump.rdb
Now, just start the Redis server.
In case it is AOF mode. ('yes'), it involes a bit more process. The first thing to do is the same as previos case, just stop the redis server
Go inside directory where dump.rdb is located
After that, clean dump.rb and appendonly.aof files up
rm -f dump.rdb appendonly.aof
Copy the backup file in the place, along the line, correct its permission.
cp /backup/dump.rdb /var/lib/redis/ chown redis:redis /var/lib/redis/dump.rdb
The important part is to disable AOF by editing /etc/redis/redis.conf file, set appendonly as no
Run the following command to create new appendonly.aof file
Next, start the Redis server and issue the BGREWRITEAOF command:
/etc/init.d/redis-server start redis-cli BGREWRITEAOF
Check the progress (0 - done, 1 - not yet)
redis-cli info | grep aof_rewrite_in_progress
You should see a new appendonly.aof file. Next, stop the server.
After it finished, enable AOF again by changing appendonly in /etc/redis/redis.conf file to yes
Then start the redis server again.
And we are done.