Failed opening the RDB file ... Read-only file system

Question

I'm trying to perform a save or bgsave on my redis instance to run through the backup/restore process. I'm getting errors when I try to save however:

532:M 28 Jun 23:58:30.396 # Failed opening the RDB file backup.rdb (in server root dir /var/lib/redis) for saving: Read-only file system

Permissions on the /var/lib/redis folder:

$@/var/lib$ ls -artl | grep redis
drwxrwxrwx  3 redis    redis    4096 Jun 28 23:58 redis

Permissions on the /var/lib folder:

$@/var$ ls -artl | grep lib
drwxrwxrwx 31 root root  4096 Jun 28 23:44 lib

Permissions on the /var folder:

$@/$ ls -artl | grep var
drwxrwxrwx  11 root root  4096 Jul 18  2016 var

Redis CLI output for config get dir:

1) "dir"
2) "/var/lib/redis"

Redis CLI output for config get dbfilename:

1) "dbfilename"
2) "backup.rdb"

Error from redis:

532:M 28 Jun 23:58:30.396 # Failed opening the RDB file backup.rdb (in server root dir /var/lib/redis) for saving: Read-only file system

Any help would be much appreciated!

Answer 1

You need to add the following to your /etc/systemd/system/redis-server unit file:

ReadWriteDirectories=-/var/lib/redis

Note that /var/lib/redis is the default, but if in your /etc/redis/redis.conf you set a different dir config option, you will need to set ReadWriteDirectories to that.