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Date:      Thu, 14 May 2015 00:21:05 +0300
From:      Konstantin Kukushkin <dark@rambler-co.ru>
To:        motty cruz <motty.cruz@gmail.com>
Cc:        =?UTF-8?B?VHJvbmQgRW5kcmVzdMO4bA==?= <Trond.Endrestol@fagskolen.gjovik.no>, freebsd-questions@freebsd.org
Subject:   Re: Help! carp slave take over as master at boot!
Message-ID:  <5553C041.7050903@rambler-co.ru>
In-Reply-To: <CALoOYy7doZusm6bWHtV7wkQaC4kkr6Sd-8vWxSLEvky04gwpDQ@mail.gmail.com>
References:  <55511AF3.3030408@gmail.com>	<alpine.BSF.2.20.1505120742290.46962@mail.fig.ol.no>	<CALoOYy6Tb3Pc2fLJFnQE+z85Mwc1_eSTYBD8T=j4vo-i8kCRmg@mail.gmail.com>	<55531870.9060607@rambler-co.ru> <CALoOYy7doZusm6bWHtV7wkQaC4kkr6Sd-8vWxSLEvky04gwpDQ@mail.gmail.com>

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13.05.2015 20:58, motty cruz пишет:
> Hello Konstantin
>
> This is a new setup; my goal is to have a redundant "file server"; if
> "Machine A(master) goes down or just reboot for any reason, I want
> Machine B(slave) to take over as Master and I want Machine (B slave) to
> stay Master when Machine A come back on-line.
>
> Here is what I have thus far:
> Machine A (master)
> ifconfig_igb0_alias0="inet vhid 31 advbase 12 advskew 40 pass password2
> 19.16.31.80/24 <http://19.16.31.80/24>"
>
> Machine B (slave)
> ifconfig_igb0_alias0="inet vhid 31 advbase 12 advskew 80 pass  password2
> 19.16.31.80/24 <http://19.16.31.80/24>"
> both machines: /etc/sysctl.conf
> # net.inet.carp.preempt=1
>
> (Machine A ) /etc/devd.conf
> ##### Check status of CARP interface ########
> notify 5 {
>                     match "system"          "CARP";
>                     match "subsystem"       "[0-9]+@[0-9a-z]+";
>                     match "type"            "(MASTER)";
>                     action "/usr/local/sbin/startmaster.pl
> <http://startmaster.pl>";
> };
>
> notify 5 {
>          match "system"          "CARP";
>          match "type"            "[0-9]+@[0-9a-z]+";
>          match "subsystem"       "(BACKUP)";
>          action "/usr/local/sbin/slave.sh";
> };
>
>
> (Machine B) /etc/devd.conf
> ### Check status of CARP interface  ###
> notify 5 {
>                     match "system"          "CARP";
>                     match "subsystem"       "[0-9]+@[0-9a-z]+";
>                     match "type"            "(MASTER)";
>                     action "/usr/local/sbin/startmaster.pl
> <http://startmaster.pl>";
> };
>
>
>
> notify 5 {
>          match "system"          "CARP";
>          match "type"            "[0-9]+@[0-9a-z]+";
>          match "subsystem"       "(BACKUP)";
>          action "/usr/local/sbin/slave.sh";
> };
>
> if Master machine reboots, I want slave to take over as Master and stay
> Master even after Machine with lowest advskew come back online.
>
> any ideas?

If you want address switched only if neighbour is died you need to take 
carp preemtion off, i.e. net.inet.carp.preempt=0 on both machines.
Explanation from carp(4):
net.inet.carp.preempt - Allow virtual hosts to preempt each other.  When 
enabled, a vhid in a backup state would preempt a master that is 
announcing itself with a lower advskew.  Disabled by default.

Enabling this option need for setup where one server main and another 
server for fallback, working if (and only if) main server is died.

Pay attention that carp detect that neighbour is died if 3 packet was 
lost, so on your setup "switch" time will be between 36 and 48 seconds.

> Thanks,
> Motty
>
>
>
> On Wed, May 13, 2015 at 2:25 AM, Konstantin Kukushkin
> <dark@rambler-co.ru <mailto:dark@rambler-co.ru>> wrote:
>
>     13.05.2015 04:19, motty cruz пишет:
>
>         Hi thanks for your reply;
>
>         Machine A (master)
>         ifconfig_igb0_alias0="inet vhid 31 advbase 12 advskew 40 pass
>         password2
>         19.16.31.80/24 <http://19.16.31.80/24>"
>
>         Machine B (slave)
>         ifconfig_igb0_alias0="inet vhid 31 advbase 12 advskew 80 pass
>         password2
>         19.16.31.80/24 <http://19.16.31.80/24>"
>
>         if I reboot slave, on boot it takes over as Master, any idea why?
>         both machines: /etc/sysctl.conf
>         # net.inet.carp.preempt=1
>
>
>     I don't understand master was rebooted so check runtime
>     configuration of sysctl net.inet.carp.preempt on master.
>     Check also /var/log/messages on both computers, sysctl
>     net.inet.carp.demotion on master (CARP may be demoted due to
>     interface/pfsync errors. CARP with preemption may be demoted also by
>     down any other interface with CARP on the system).
>     Check firewall on slave, may be it block ingress packets from master.
>
>
>         On Mon, May 11, 2015 at 10:45 PM, Trond Endrestøl <
>         Trond.Endrestol@fagskolen.gjovik.no
>         <mailto:Trond.Endrestol@fagskolen.gjovik.no>> wrote:
>
>             On Mon, 11 May 2015 14:11-0700, Motty Cruz wrote:
>
>                 Hello, I have two machines running FreeBSD 10.1 Release.
>                 Machine A is the
>                 master in Carp with advskew 20 and Machine B slave with
>                 advskew 200 both
>
>             are
>
>                 set to advbase 10. however, slave machine becomes Master
>                 on boot;
>
>                 my questions is, how do I configure both machines so if
>                 reboot any of the
>                 machines whatever machine is Master stays master if
>                 secondary machine
>
>             reboot.
>
>             You should augment your posting with facts. You may withhold any
>             sensitive information such as IP addresses, but a copy of
>             the relevant
>             lines from /etc/rc.conf and /etc/sysctl.conf would be helpful.
>
>             Have you tried setting:
>
>             net.inet.carp.preempt=1
>
>             in /etc/sysctl.conf?
>
>             Try the command:
>
>             sysctl net.inet.carp.preempt=1
>
>             to see any immediate effect.
>
>             --
>             +-------------------------------+------------------------------------+
>             | Vennlig hilsen,               | Best regards,
>                      |
>             | Trond Endrestøl,              | Trond Endrestøl,
>                       |
>             | IT-ansvarlig,                 | System administrator,
>                      |
>             | Fagskolen Innlandet,          | Gjøvik Technical College,
>             Norway,  |
>             | tlf. mob.   952 62 567,       | Cellular...: +47 952 62
>             567 <tel:%2B47%20952%2062%20567>,       |
>             | sentralbord 61 14 54 00.      | Switchboard: +47 61 14 54
>             00 <tel:%2B47%2061%2014%2054%2000>.      |
>             +-------------------------------+------------------------------------+
>
>
>
>     --
>     С уважением, Константин Кукушкин,
>     Rambler Internet Holding
>     mailto:dark@rambler-co.ru <mailto:dark@rambler-co.ru>
>     тел.: 8 (495) 785-17-00#2129
>
>
>
>
> --
> Thanks for your support,
> Motty


-- 
С уважением, Константин Кукушкин,
Rambler Internet Holding
mailto:dark@rambler-co.ru
тел.: 8 (495) 785-17-00#2129



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