title: Why almost every command is trying to read urandom?
body: <p>In a recent kernel(5.x) / rootfs for an embedded system (mips/MT7628/busybox, if it matters) I see TONS of:</p>
  
  <pre><code>random: mount: uninitialized urandom read (4 bytes read)
  random: fsck.vfat: uninitialized urandom read (4 bytes read)
  random: tar: uninitialized urandom read (4 bytes read)
  ...
  </code></pre>
  
  <p>This stops when, after a while (~10min!!) I finally see:</p>
  
  <pre><code>[  562.001438] random: crng init done
  </code></pre>
  
  <p>Two questions:</p>
  
  <ol>
  <li>why does it take so long to initialize /dev/urandom?</li>
  <li>for what reason <code>mount</code> or <code>tar</code> should try to use it in the first place?</li>
  </ol>
  
  <p>Note: I did NOT have this problem with older kernels (3.x).</p>