Redis ＂MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk＂问题的解决

原文：http://pydelion.com/2013/05/27/redis-cant-save-in-background-fork-cannot-allocate-memory/ If you get this error Can‘t save in background: fork: Cannot allocate memory it means that your current database is bigger than memory you have. To fix the issue enable vm.overcommit_memory: sysctl vm.overcommit_memory=1 To have if after reboot add this line to /etc/sysctl.cnf: vm.overcommit_memory=1

修改vm.overcommit_memory=1后问题果然解决了。

为什么系统明明还剩2GB的内存，Redis会说内存不够呢？

网上查了一下，有人也遇到类似的问题，并且给出了很好的分析（详见：http://www.linuxidc.com/Linux/2012-07/66079.htm）， 简单地说：Redis在保存数据到硬盘时为了避免主进程假死，需要Fork一份主进程，然后在Fork进程内完成数据保存到硬盘的操作，如果主进程使用了 4GB的内存，Fork子进程的时候需要额外的4GB，此时内存就不够了，Fork失败，进而数据保存硬盘也失败了。

Redis ＂MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk＂问题的解决

标签：