<p>There are no "specs" as to how a sparse file is handled in response to writes.</p>
<p>Sparse is mostly beneficial when the holes are very large.</p>
<p>If an app really wants to have minimal on disk space, you should pre-allocate space with fallocate.</p>
<p>You may even need to hole punch after the writes. Both xfs and ext4 support both fallocate and hole punching. (I don't know the userspace call to hole punch. I think its a relatively new feature for ext4.)</p>
<p>Greg</p>
<div class="gmail_quote">On Aug 4, 2011 10:16 PM, "Ashish Sangwan" <<a href="mailto:ashishsangwan2@gmail.com">ashishsangwan2@gmail.com</a>> wrote:<br type="attribution"></div>