title: Unable to save in background (redis-server)
body: <p>I have two redis servers running on the same machine. The second one's log files have several instances with notices such as these:</p>
  
  <pre><code>[50818] 19 Feb 06:41:05.007 * 10 changes in 300 seconds. Saving...
  [50818] 19 Feb 06:41:05.007 # Can't save in background: fork: Cannot allocate memory
  </code></pre>
  
  <p>In contrast, the log files of the first one solely contain successful DB saves. If I were out of memory, I reckon both would have similar logs. It perplexes me that only one has this problem, the other doesn't. Any leads?</p>
  
  <p>Moreover, research led me to <a href="https://pydelion.com/2013/05/27/redis-cant-save-in-background-fork-cannot-allocate-memory/" rel="noreferrer">this blog post</a>, which contends that the issue can be ameliorated if I do <code>sysctl vm.overcommit_memory=1</code> on the command line. There's no explanation of how this helps. Can someone explain what's going on here in context of redis?  </p>