我在使用AFS磁盘空间的服务器上工作时遇到了这个问题，因为我的身份验证令牌已经过期，当redis-server试图保存时产生了Permission Denied响应。我通过刷新我的令牌来解决这个问题:

kinit USERNAME_HERE -l 30d && aklog

在redis.conf第235行，让我们像这样修改配置

- stop-writes-on-bgsave-error yes
+ stop-writes-on-bgsave-error no

此错误是由于BGSAVE失败导致的。在BGSAVE期间，Redis会fork一个子进程来将数据保存到磁盘上。虽然BGSAVE失败的确切原因可以从日志中检查(通常在linux机器上的/var/log/redis/redis-server.log)，但很多时候bgive失败是因为fork不能分配内存。很多时候，由于操作系统的优化冲突，fork无法分配内存(尽管机器有足够的可用RAM)。

可以从Redis常见问题中阅读:

Redis background saving schema relies on the copy-on-write semantic of fork in modern operating systems: Redis forks (creates a child process) that is an exact copy of the parent. The child process dumps the DB on disk and finally exits. In theory the child should use as much memory as the parent being a copy, but actually thanks to the copy-on-write semantic implemented by most modern operating systems the parent and child process will share the common memory pages. A page will be duplicated only when it changes in the child or in the parent. Since in theory all the pages may change while the child process is saving, Linux can't tell in advance how much memory the child will take, so if the overcommit_memory setting is set to zero fork will fail unless there is as much free RAM as required to really duplicate all the parent memory pages, with the result that if you have a Redis dataset of 3 GB and just 2 GB of free memory it will fail. Setting overcommit_memory to 1 says Linux to relax and perform the fork in a more optimistic allocation fashion, and this is indeed what you want for Redis.

Redis不需要像操作系统认为的那样多的内存来写入磁盘，所以可能会预先导致fork失败。

要解决这个问题，您可以:

修改/etc/sysctl.conf，增加:

vm.overcommit_memory=1

然后重新启动sysctl:

在FreeBSD上:

sudo /etc/rc.d/sysctl reload

在Linux上:

sudo sysctl -p /etc/sysctl.conf

您必须chmod和chown新文件夹

chown -R redis chmod…

# on redis 6.0.4 
# if show error 'MISCONF Redis is configured to save RDB snapshots'
# Because redis doesn't have permissions to create dump.rdb file
sudo redis/bin/redis-server 
sudo redis/bin/redis-cli

请注意，当您的服务器受到攻击时，将出现此错误。刚刚发现redis无法写入'/etc/cron。D /web'，在修改权限后，添加了包含挖掘算法和一些隐藏选项的新文件。