Unbreakable Linux

Designing Unbreakable Linux System

[zscherween]

Designing a robust system on Linux may get you lost if you don't know where to find the right information. I have prepared here my experience during my journey. This topic covers redundant system to maximize system uptime.<br>

INGREDIENTS:
Mandrake Linux 9+ (mandrake.com)
-Apache, PHP, Perl, firewall system
Heartbeat (linux-ha.org)
Postgres DBMS
2 Server machine
-Pentium
-64MB
-GB hard disk
-3 NIC (LAN-0,LAN-1 & LAN-2)
2 HUB (HUB-0 & HUB-1)

The 2 server are connected via crosscable thru their LAN-0. The heartbeat is setup to communicate via LAN-0 on each server. One server should be configured as Main and one as backup server.

LAN-1 of both server are connected to HUB-0, where the DSL modem is also connected. This would be the external network segment.

LAN-2 of both server are connected to HUB-1, this internel network segment.

Set both server to sync data via rsync. To syncronize data on both server. (I think there are other method of doing this, let me know)

You may also setup clustering system on HUB-2, which will distriute load amongs servers. This would be for future expansion.

I know this setup quite simple. If you have comments on how I can make this better, please let me know.

[bakedjake]

What about:

RAID, and redundant RAID?
Dual Controllers?
Dual Power Supplies?
Dual Processors?

I've had all of those fail on me at some point, and they're much more frequent failures than the network, IMHO.

Don't forget redundant external connectivity. I didn't see that mentioned on your list either. And power.

[zscherween]

In this setup the two computer act as a redundant system. They can both have their own RAID system. If the budget allows, we can add an external data store, that both computer accessed. That would require redundancy too.
Regarding power, there are alternatives. 1.Deisel Generator 2. Solar Power Backup systems. 3.Power Inverter System.

There are many possible setup when it comes to this. Sometimes, budget defines.

[RussellC]

Our Intranet runs off of a Compaq Blade Server with a RAID setup, redundant power supplies, redundant memory, and battery backup. It runs Redhat 8.0 with all of the goodies. We turned the thing on almost exactly one year ago and it has only been rebooted 1 time, and that was only because we felt like we should for some reason, it didn't need it. I wish I could say the same for the Exchange Server. I think your plans sound good, but you can never be too careful.