# Redis: (error) ERR CONFIG SET failed (possibly related to argument 'maxmemory') - can't set immutable config

**Code:** `ERR CONFIG SET failed (possibly related to argument)` · **Category:** Redis · **Seen on:** Redis, Linux

`CONFIG SET` rejected the parameter — it is immutable at runtime, invalid, or disabled by the hosting provider.

## Meaning

Some settings (`bind`, `port`, `daemonize`) need a restart, so edit `redis.conf` instead. Others fail due to invalid values/units (`maxmemory 2gb`). Managed Redis (ElastiCache, Memorystore, Azure) blocks `CONFIG` and uses parameter groups/portal settings. Check `CONFIG GET param` for valid values and `INFO server` for the version.

## Common causes

- Immutable parameter (needs restart)
- Invalid value or unit
- CONFIG renamed/disabled (`rename-command CONFIG ""`)
- Managed service blocking CONFIG
- ACL without `+config`

## Quick fix

1. Edit `redis.conf` and restart for immutable settings
2. Use the provider's parameter group/portal
3. Check `ACL GETUSER` for `+config` and `rename-command` lines

## Detailed fix by platform

### Linux

1. `redis-cli CONFIG GET maxmemory; redis-cli CONFIG SET maxmemory 2gb`

## How to diagnose

1. **Parameter** — Mutable?
2. **Provider** — Managed?
3. **ACL** — config allowed?

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Source: [WhatIsMyError](https://whatismyerror.com/errors/redis/err-config-set-failed-possibly-related-to-argument)