<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Oct 12, 2012, at 10:33 AM, Justin Hurley <<a href="mailto:justin.hurley@opensgi.com">justin.hurley@opensgi.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><font face="comic sans ms" size="1"><div style="margin: 0px; padding: 0px; font-family: arial; font-size: 10pt; ">Hello All,</div><p style="margin:0;padding:0;font-family: arial; font-size: 10pt;"> </p><div style="margin: 0px; padding: 0px; "><span style="font-family: arial; font-size: 10pt;">I am having problems with some instances not receiving DCHPACK from my VM's dhcp server after extended periods of time. These instances are running heavy network, I/O, and RAM loads when the DHCPREQUEST does not receive a response. Note that this only happens to a handful of instances, not all instances running the exact same load. I have printed a relevant section of the syslog below.</span></div><p style="margin:0;padding:0;"> </p><div style="margin: 0px; padding: 0px; "><span style="font-family: arial; font-size: 10pt;">My current environment is a multi-host flat dhcp network with nova-network running on each node. </span><span style="font-family: arial; font-size: small;">All servers and VM's are running Ubuntu 12.04 and using kvm/libvirt. </span><span style="font-family: arial; font-size: small;">I am also using large NFS servers to transfer big files to and from instances across the VM network. </span></div><p style="margin:0;padding:0;"> </p><div style="margin: 0px; padding: 0px; "><span style="font-family: arial; font-size: 10pt;">In the past, I used Eucalyptus and the same problem would occur. This tends to happen more frequently with more VMs and overall network load. </span></div><p style="margin:0;padding:0;"> </p><div style="margin: 0px; padding: 0px; "><span style="font-family: arial; font-size: 10pt;">If anyone has any ideas as to why the dhcp server stops responding to only a few instances occasionally please let me know.</span></div></font></blockquote><br></div><div>I haven't seen this before, but you may be able to work around the issue by setting much longer leases:</div><div><br></div><div><br></div><div>force_dhcp_release=True</div><div>dhcp_lease_time=86400 # 1 day leases</div><div>fixed_ip_disassociate_timout=172800 # 2 day timeout</div><div><br></div><div><br></div><div>Vish</div><div><br></div><br></body></html>