How to Fix Redis MISCONF Error

Fixing the Redis MISCONF Error

The Redis MISCONF error -- "Redis is configured to save RDB snapshots, but it is currently not able to persist on disk" -- occurs when Redis cannot write its data to disk. This causes all write operations to fail, breaking applications that depend on Redis caching or session storage on your Breeze.

Common Causes

• Disk full -- no space remaining for the RDB dump file
• Incorrect file permissions on the Redis data directory
• A background save process failed due to memory constraints

Immediate Fix

Allow writes temporarily while you resolve the underlying issue:

redis-cli config set stop-writes-on-bgsave-error no

This is a temporary workaround. You must fix the root cause to prevent data loss.

Check Disk Space

df -h /var/lib/redis
du -sh /var/lib/redis/dump.rdb

Free up disk space if the volume is full.

Fix Permissions

sudo chown -R redis:redis /var/lib/redis
sudo chmod 750 /var/lib/redis

Check for Memory Issues

Redis forks a child process for background saves, temporarily doubling memory usage:

redis-cli info memory | grep used_memory_human
free -h

If your Breeze is low on RAM, enable overcommit:

sudo sysctl vm.overcommit_memory=1
echo "vm.overcommit_memory=1" | sudo tee -a /etc/sysctl.conf

Verify the Fix

redis-cli bgsave
redis-cli lastsave

If bgsave completes without errors and lastsave shows a recent timestamp, Redis persistence is working correctly again.