Load sharing on network

I have a fairly high end home built Server, 5 disk (SCSI) raid, UPS, Dual
PSU, etc, etc.

It basically runs all my home automation stuff, ranging from alarms, to
heating, as well as acting as mail, print and file server.

What I would like to do is build another identical system as a backup - in
case of Motherboard, SCSI backplane failure, etc; and have it 'ready' on the
Network.

I can keep the two systems synchronised, but how could I get one to take
over automatically if the other one fails?

Thanks

Clive

"Clive" <(E-Mail Removed)> wrote in message
news:lAILd.4287$(E-Mail Removed) k...
> I have a fairly high end home built Server, 5 disk (SCSI) raid, UPS, Dual
> PSU, etc, etc.
>
> It basically runs all my home automation stuff, ranging from alarms, to
> heating, as well as acting as mail, print and file server.
>
> What I would like to do is build another identical system as a backup - in
> case of Motherboard, SCSI backplane failure, etc; and have it 'ready' on
the
> Network.
>
> I can keep the two systems synchronised, but how could I get one to take
> over automatically if the other one fails?
>
> Thanks
>
> Clive
>
>
Clive,

I think you're out of this NG's depth here. You are asking a very
complicated question which depends no many things. For example, does your
server just "react" to external stimuli, for example a temporature censor
connects to the server and sends "I'm too hot" or is it a client, connecting
the the sensor and saying "how hot are you"? Having back-up requires very
different handling for these two situations.

Also, I have to ask WHY? You have a system far, far more redundant that any
normal person would have (and most companies for that matter!) so why do you
feel the need for even more back-up?

Anyway, I suggest you ask a more technical NG, sorry I don't know of one,
and ask about things such as "replication of state". As a hint, if the
systems are intelligent (e.g. e-mail server), they need to keep identical
copies of everything i.e. need to replicate between themselves, so that an
external user sees absolutely no difference between the two servers when
they "swap". This is complex stuff and not for the faint hearted!

Good luck,
Paul DS.

On Tue, 01 Feb 2005 10:10:25 GMT, "Clive" <(E-Mail Removed)> strung
together this:

>I have a fairly high end home built Server, 5 disk (SCSI) raid, UPS, Dual
>PSU, etc, etc.
>
>It basically runs all my home automation stuff, ranging from alarms, to
>heating, as well as acting as mail, print and file server.
>
>What I would like to do is build another identical system as a backup - in
>case of Motherboard, SCSI backplane failure, etc; and have it 'ready' on the
>Network.
>
>I can keep the two systems synchronised, but how could I get one to take
>over automatically if the other one fails?
>
I'd have to agree with Paul here.

I would have thought that you'd be better off, and it would also make
the task easier, if you had parts to hand to replace in the main
server.

The only thing that would cause a major problem would be a
catastrophic failure of the RAID array. I'd be inclined to set up a
backup file server rather than a complete mirror image server.
--

SJW
Please reply to group or use 'usenet' in email subject

In MsgID<lAILd.4287$(E-Mail Removed). uk> within
uk.comp.home-networking, 'Clive' wrote:

>I can keep the two systems synchronised, but how could I get one to take
>over automatically if the other one fails?

Before that question can be answered you'll need define 'working' in terms
of things that the backup machine can monitor. The backup either needs to
directly watch the normal activity to/from the main server, or if all
you're protecting against is a 'total' crash then a heartbeat system might
be right.

By 'heartbeat' I mean a little proggy on the main machine that regularly
either sends a ping or makes a full connection to the backup, so that the
backup can know if it has failed.

How it should then go about 'taking over' probably depends on the details
of your setup. Perhaps if you say how you would manually initiate the
swap?

Both machines set to the same IP is the obvious answer, but then they
can't both be active at the same time. I'm interested in answers to your
question too, but I really do think you'll need to describe the system in
a little more detail.

--
Dave Johnson - (E-Mail Removed)

In article <lAILd.4287$(E-Mail Removed)> , "Clive"
(E-Mail Removed) says...
> I have a fairly high end home built Server, 5 disk (SCSI) raid, UPS, Dual
> PSU, etc, etc.
>
> It basically runs all my home automation stuff, ranging from alarms, to
> heating, as well as acting as mail, print and file server.
>
> What I would like to do is build another identical system as a backup - in
> case of Motherboard, SCSI backplane failure, etc; and have it 'ready' on the
> Network.
>
> I can keep the two systems synchronised, but how could I get one to take
> over automatically if the other one fails?
>
http://www.linux-ha.org/

http://www.microsoft.com/windows2000...ng/default.asp

"Rob Morley" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) t...
> In article <lAILd.4287$(E-Mail Removed)> , "Clive"
> (E-Mail Removed) says...
>> I have a fairly high end home built Server, 5 disk (SCSI) raid, UPS, Dual
>> PSU, etc, etc.
>>
>> It basically runs all my home automation stuff, ranging from alarms, to
>> heating, as well as acting as mail, print and file server.
>>
>> What I would like to do is build another identical system as a backup -
>> in
>> case of Motherboard, SCSI backplane failure, etc; and have it 'ready' on
>> the
>> Network.
>>
>> I can keep the two systems synchronised, but how could I get one to take
>> over automatically if the other one fails?
>>
> http://www.linux-ha.org/
>
> http://www.microsoft.com/windows2000...ng/default.asp

Thanks for all the answers guys.

I work from home and over the past few years I've just added more and more
automation around the house. I designed and built most of the house myself.

My server (Windows Server 2003) runs just about everything in the house:

Heating, water system
Alarm system(s) including wireless cameras
Multiroom audio/video
Mail, File and print server
Garage doors
Most appliance can also be controlled from it or a GPRS phone
It also switches over to a backup generator should my power fail
Plus all the usual stuff, printer, scanner, etc.

As you can appreciate, if it went down, it would cause me a lot of problems.

I think I'll read the stuff on Clustering - that seems the way to go.

Server specs Dual Xeon, 2gb RAM, 5x36 10k SCSI drives (hot swappable, 1
spare).
Adaptec Raid card
2 hot swappable 550watt PSU's
2 10/100 copper network cards
1 1gb Fibre NIC

All house in a 19" rack with associated patch panels

Clive

On Tue, 01 Feb 2005 19:13:30 GMT, "Clive" <(E-Mail Removed)> wrote:

[snipped]

>I work from home and over the past few years I've just added more and more
>automation around the house. I designed and built most of the house myself.
>
>My server (Windows Server 2003) runs just about everything in the house:

[snipped]

>As you can appreciate, if it went down, it would cause me a lot of problems.

Yes, dreadful experience, back to wiping your arse manually :-)

--
Jeff Gaines

In MsgID<(E-Mail Removed)> within
uk.comp.home-networking, 'Jeff Gaines' wrote:

>>As you can appreciate, if it went down, it would cause me a lot of problems.
>
>Yes, dreadful experience, back to wiping your arse manually :-)

Aww, leave him be, it interests me to see the way people extend computer
control to all aspects of a household. I personally would probably never
bother as I don't have enough 'hobby time' left over for such a project,
but I think that in the future when most houses have a network star as
automatically as most houses have a mains loop there will be a significant
growth in such things.

At the end of the day it does make sense, most things are microprocessor
controlled, so if you take the obvious step of linking each unit to a
central controller then it imparts a nice bit of synchronisation to the
chaos..

The only snag being, as the OP says, you're creating a central point of
failure.

--
Dave Johnson - (E-Mail Removed)

"Clive" <(E-Mail Removed)> wrote in message
news:lAILd.4287$(E-Mail Removed) k...
>I have a fairly high end home built Server, 5 disk (SCSI) raid, UPS, Dual
>PSU, etc, etc.
>
> It basically runs all my home automation stuff, ranging from alarms, to
> heating, as well as acting as mail, print and file server.
>
> What I would like to do is build another identical system as a backup - in
> case of Motherboard, SCSI backplane failure, etc; and have it 'ready' on
> the Network.
>
> I can keep the two systems synchronised, but how could I get one to take
> over automatically if the other one fails?
>

Would be very interested on details of your setup.
I can't really help with the question but its something I would like to do
in the future.

If you have a moment - i buy my cars at ntlworld dot com

remove the spacing and replace cars with clothes

Neil

On Tue, 01 Feb 2005 19:13:30 GMT, "Clive" <(E-Mail Removed)> wrote:

>
[...]
>
>Thanks for all the answers guys.
>
>I work from home and over the past few years I've just added more and more
>automation around the house. I designed and built most of the house myself.
>
>My server (Windows Server 2003) runs just about everything in the house:
>
>Heating, water system
>Alarm system(s) including wireless cameras
>Multiroom audio/video
>Mail, File and print server
>Garage doors

Well here you have separate applications presumably controling the
equipment, you need to ask the suppliers of the equipment how the heck
they manage in a clustered environment.

>Most appliance can also be controlled from it or a GPRS phone
>It also switches over to a backup generator should my power fail
>Plus all the usual stuff, printer, scanner, etc.

What about backup media?

To be onist, you are giving yourself a really big project. Why not
look at the cost of getting either a separate server or spare parts,
then if/when the first machine goes down, you can swap over disks,
make restores if necessary, or change hardware.

Andrew.
--
Andrew Hodgson in Bromyard, Herefordshire, UK.
My Email: use <andrew at hodgsonfamily dot org>.