# Remote Install/recovery strategy



## leebrown66 (Oct 30, 2014)

Dear experts,

I'm planning to migrate our CentOS6 gateways (running DNS, DHCP, NTP, Squid, Snort, Firewall) to FreeBSD. I only have a handful of servers, but most are remote and are a variety of hardware (not all have IPMI). We have power issues at one location and while it's UPS backed, there's no notification when it's running on UPS (Yes I need to purchase the SNMP card) so the systems don't shutdown gracefully when running low on time.

I was considering configuring the BIOS to boot from HDD, then fallback to PXE. The idea being if, for some reason, a catastrophic disk failure occurred, preventing a HD boot, I would still be able to bring up a FreeBSD instance over PXE/NFS and log into it and maybe address the issue.

If FreeBSD boots into single user mode, my investigations indicate that serial console is the only option in this case. As these are the gateway machines, if it's down, there's no network access, so I'd need to set[]up failover with CARP on another system at the same location, which doesn't seem so reliable. 

However, if that secondary system (laptop/old PC) ran with / mounted ro, would that isolate it from HDD issues if the power went out, as there would be no possibility of malformed disk updates. I'd only need the firewall up on this system.

Any advice and/or real-world examples of how other folk have managed this would be most welcomed.

Thanks for reading through this,
Lee


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## wblock@ (Oct 30, 2014)

A lot going on there.

Just for a start, if the UPS is one that sysutils/apcupsd can talk to, one computer can speak directly to the UPS by USB or serial.  Other computers run a client which talks to that UPS server, no additional hardware needed.


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## leebrown66 (Nov 3, 2014)

wblock@ said:


> Just for a start, if the UPS is one that sysutils/apcupsd can talk to, one computer can speak directly to the UPS by USB or serial.  Other computers run a client which talks to that UPS server, no additional hardware needed.


Thanks for that.  I still do have some of those units left over and had not realized that serial I/O was an option with them.


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