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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Hey all, so my re-pairing went fine that I did early Saturday morning.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>What I did was;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Stop dhcpd on both servers<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Deleted the dhcpd.leases file which sits on a 4 gig ramdisk on both servers<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Then I rebooted the primary server, I did a reboot rather than start dhcpd, as I had kernel updates to do, so I figure kill 2 birds with one stone!<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Before dhcpd starts, in the init.d script, I do a “touch /ramdisk/dhcpd.leases “<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Then dhcpd starts up fresh, all worked fine on primary, it started giving leases out after about 4 minutes after it started up.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Then after the MCLT time, I did the same thing to the secondary, and it came up flawlessly and both started to give out leases in a load balancing way just fine.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>BTW I do copy /ramdisk/dhcpd.leases file to disk every 5 mins to be safe via cron.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Other than this reboot it ran for almost a year with zero issues.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Thanks for all the comments.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Have a great day!<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'>Rob Morin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'>Gestionnaire des systèmes | Senior Systems Administrator<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'>Tel: 514 385-4448 #174 <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'>DATAVALET.COM<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'>5275, chemin Queen-Mary, Montréal (Québec) H3W 1Y3 Canada<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'>CE COURRIEL AINSI QUE CES DOCUMENTS JOINTS peuvent contenir des renseignements confidentiels et privilégiés. Si vous n’êtes pas le destinataire désigné, veuillez nous en informer immédiatement et effacer toute copie. Merci.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:black'>THIS EMAIL AND THE DOCUMENTS ATTACHED may contain privileged or confidential information. If the reader of this message is not the intended recipient, please notify the sender immediately and delete the original message. Thank you.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> dhcp-users [mailto:dhcp-users-bounces@lists.isc.org] <b>On Behalf Of </b>Bob Harold<br><b>Sent:</b> January 16, 2017 2:49 PM<br><b>To:</b> Users of ISC DHCP <dhcp-users@lists.isc.org><br><b>Subject:</b> Re: DHCP pair messed up, second one only running cant get primary up.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div><div><div><p class=MsoNormal><o:p> </o:p></p></div></div><div><p class=MsoNormal>On Mon, Jan 16, 2017 at 12:14 PM, Drew Derbyshire <<a href="mailto:swhobbit@derbyshire.us" target="_blank">swhobbit@derbyshire.us</a>> wrote:<o:p></o:p></p><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal>As an aside ...<br><br>The thought of putting recovery state/log files (i.e. the DHCP leases file and its backup) on a RAM disk to make top look pretty leaves me dismayed. That leaves zero local protection against a system crash (or misguided deliberate reboot).<br><br>And yes, the server has been running 346 days -- Doesn't matter. Services can be five nines reliable, but hardware won't be.<br><br>An SSD, or if you prefer multiple SSD units configured as a raid, will give you the same order of performance without the premortem fodder.<br><br>The machine should be audited for other critical files which are written to volatile storage, and moved to the SSD or other storage as well.<br><br>-ahd-<o:p></o:p></p><div><div><p class=MsoNormal><o:p> </o:p></p></div></div></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I agree that putting state in ram is a concern, but with a failover pair, there should be a duplicate copy on the other server of all but the very latest changes. There is a risk when one server is rebooting, so having a copy of the backup lease file on real disk would help.<o:p></o:p></p></div><div><p class=MsoNormal>I think SSD (particularly write speed) is still orders of magnitude slower than ram.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>That said, I would not ever want to have both servers rebooted at the same time, or even restart DHCP at the same time. Restart one, allow it to sync data and get to normal-normal, then restart the other.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>-- <o:p></o:p></p></div><div><p class=MsoNormal>Bob Harold<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p></div></div></div></body></html>