Redis 'MISCONF Redis is configured to save RDB snapshots, but it's currently unable to persist to disk. Commands that may modify the data set are disabled' - how do I fix it?

Cause: Redis is set to take RDB snapshots and the most recent background save failed. With the default stop-writes-on-bgsave-error yes, Redis then refuses write commands so a failing disk does not go unnoticed (reads still work). Typical reasons: the data directory (dir) is full or read-only, the Redis user lacks write permission there, or the background save's fork() failed for lack of memory. Fix (best first): 1. Read the Redis log around the failed save; it names the reason. Then check df -h and df -i for the volume, and that the directory in CONFIG GET dir is writable by the redis user. 2. Free or add disk space, or fix ownership and mount flags so the redis user can write the RDB file, then trigger a save with BGSAVE. Writes resume automatically once a background save succeeds. 3. If the log shows a fork failure, give the host enough memory: Redis may need up to about twice the dataset memory during a save for write-heavy workloads, and the Redis admin guide advises setting vm.overcommit_memory = 1 in /etc/sysctl.conf (sysctl vm.overcommit_memory=1). Also set maxmemory below physical RAM with headroom. 4. In containers, make sure the data directory is a mounted volume with space and correct permissions. 5. Only if you accept losing data (a pure cache) should you disable persistence on purpose with save "" . Setting stop-writes-on-bgsave-error no hides persistence failures, so use it only when you monitor INFO persistence (rdb_last_bgsave_status) yourself. Verify: redis-cli INFO persistence shows rdb_last_bgsave_status:ok, and a test SET succeeds. Sources: https://raw.githubusercontent.com/redis/redis/unstable/redis.conf https://redis.io/docs/latest/develop/get-started/faq/ https://redis.io/docs/latest/operate/oss_and_stack/management/admin/