It can.  I have seldom had need to worry about it.  Most data centers have battery backups to keep power outages from crashing systems. I am also not sure if its any more or less of a risk than iscsi, except you may not be able to tell right away.  async works by basically lying to the client about the read/write.  Keep in mind that the read/write may be into a virtual machine in this case.  Even if all packets are accounted for, not completing the full stream of writing could lead to a corrupt VM filesystem anyway.  In my mind, its worth the risk for the speed.  This is also why we do backups.<br>
<br><br><div class="gmail_quote">On Fri, Mar 23, 2012 at 7:48 AM, Morgan Cox <span dir="ltr">&lt;<a href="mailto:morgancoxuk@gmail.com">morgancoxuk@gmail.com</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Thank you Gary.<div><br></div><div>After re-mounting the NFS share with async it dramatically increased the speed !</div><div><br></div><div>I can now create a 10GB virtual disk in 2 mins (rather than 10 mins)</div><div><br>


</div><div>Is using the async option more likely to cause data corruption though ?</div><div><br></div><div>Many thanks</div><div><br></div><div>Regards </div><div class="HOEnZb"><div class="h5"><div><br><div class="gmail_quote">
On 22 March 2012 21:54, Gary Scarborough <span dir="ltr">&lt;<a href="mailto:virtuallymad@gmail.com" target="_blank">virtuallymad@gmail.com</a>&gt;</span> wrote:<br>

<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br><br><div class="gmail_quote"><div><div>On Thu, Mar 22, 2012 at 12:59 PM, Morgan Cox <span dir="ltr">&lt;<a href="mailto:morgancoxuk@gmail.com" target="_blank">morgancoxuk@gmail.com</a>&gt;</span> wrote:<br>


</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div>
Hi.<div><br></div><div>After my many issues with spice I have finally sorted them out.</div><div><br></div><div>Now I am having an issue with the speed of virtual disk creation - when I go to create a virtual disk it takes a long time (far to long to be usable) </div>





<div><br></div><div>My setup is as following</div><div><br></div><div>3 servers:-</div><div><br></div><div><div>1 Frontend (ovirt engine) - Fedora 16    - external + local IP (91.215.xxx.xx + 10.0.0.10)</div><div>

1 Ovirt node (using the node .iso)   - external + local IP (ovirtmgmt (eth0) - 91.215.xxx.xxx  and LAN (eth1) - 10.0.0.101)</div><div>1 NFS storage - external + local IP - I attached the storage using the Local IP (10.0.0.190)</div>





</div><div><br></div><div>All servers are connected via a Gigabit switch (so speed should be better)</div><div><br></div><div>I can scp between servers far faster - I&#39;m almost sure its due to the node <span>ovirtmgmt address being an external (internet ip) and not LAN ip. - therefore the traffic is not just going over the gigabit switch but via the core router in the DC...</span></div>





<div><br></div><div>Can anyone suggest how I can &#39;debug&#39; where the slowness is coming from </div><div><br></div><div>On my NFS server I have it setup like (in /etc/exports)</div><div><br></div><div><div>/storage1       *(rw,sync,no_subtree_check)</div>





</div><div><br></div><div>I had previous tried setting up the node on a LAN IP previously and it caused spice to not work - as the node had no internet access / DNS - I also tried making the frontend server a gateway (and using -  iptables -t nat -A POSTROUTING -j MASQUERADE ) - this also cause spice to not work (as it always tried to connect to the 10.0.0.x address from my desktop - and fail..) </div>





<div><br></div><div>Any hints/help will be welcomed</div><div><br></div><div>Cheers</div><div><br></div><div><br></div>
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<br></blockquote></div><br>You could try async instead of sync.  You could also try thin provisioning.<span><font color="#888888"><br clear="all"><br>-- <br>Gary Scarborough<br>
IST Lab Manager<br>
Rochester Institute of Technology<br>
Rochester NY<br>
</font></span></blockquote></div><br></div>
</div></div></blockquote></div><br><br clear="all"><br>-- <br>Gary Scarborough<br>
IST Lab Manager<br>
Rochester Institute of Technology<br>
Rochester NY<br>