Looking for input on a "cold" spare

I’ve got FreePBX up and running great on a small Zotac PC (60gb SSD, 4GB Ram, Celeron processor). However, since the hardware is a bit on the lower priced side…I decided to buy two. My thoughts are that once I have the PBX up and running EXACTLY as I need it, I will just clone the hard drive to the identical hardware box. That way , if I ever encounter a failure I will already have another box ready to power on.

I realize this may cause me to lose some voicemails…but I’m thinking I can leverage the backup module to keep copies of that. Also, users will have all their voicemail emailed to them as well.

My only concern is with the commercial modules. The second box will literally never be turned on unless my primary box fails. If I clone the hard drive, will my commercial modules still register properly, should I ever need to swap the devices out?

Thank you for your input. I realize there is always the Warm Spare options…but I’m thinking more along the lines of leaving the secondary box unplugged and OFF until such a time that it is needed (hopefully never).

Yes - 2 resets are included with the Commercial Modules, so if you have to go that route, you can re-activate them on the new hardware.

Thank you! I really appreciate your time! (on both of my questions!)

There is a bit of a problem with this kind of setup: your cold spare could get horribly outdated and maybe even unable to be put back in production unless you keep it 100% synchronized package version and config-wise (especially configuration changes are not that rare as people usually think). Which means you got to keep it on too, which defeats the purpose of a ‘cold’ spare IMO.

Agreed - Automatic frequent backups (we do once a month for all our customers) to a remote server for ease of retrieval works well for us. We have machines loaded and ready to go, and if anyone dies, we pull the most recent backup to a replacement machine, and head over and bring up the replacement box - 30 minutes average replacement time and we have done it several times.

If you need quicker replacement than that, you should look at High Availability (HA) - It is very simple to setup and maintain and while it’s not cheap, if it’s a business requirement, it is what it is.

Thanks for the feedback everyone. I will definitely be utilizing automatic backups. But with your help I think I’ve decided it might be best to keep a “warm” spare…and just update it as we go so that it’s always primed and ready for action. Thanks again all!

One solution is to install “Mondo Rescue”



wget ftp://ftp.mondorescue.org/rhel/6/x86_64/mondorescue.repo -O /etc/yum.repos.d/mondorescue.repo
yum install mondo

and schedule with cron a weekly/monthly bootable DVD, USB stick or NFS mount point, you can bring the cold spare as a total clone of the hot guy up to date at anytime without even a network if USB or DVD. I bare-iron reinstall would take only a few minutes.

You can change your mac address in /etc/rc.local to keep the network from changing

sed -i ‘s/^([UH])/#\1/’ /etc/sysconfig/network-scripts/ifcfg-eth0

then add:-

/etc/init.d/network stop
ip link set eth0 address DE:AD:BE:EF:00:AA
/etc/init.d/network start

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Wow I wasn’t even aware of Mondo at all. Thanks and I WILL be doing this for sure. Thanks again for your time and responses!