Re: [cobalt-users] StaQWare for RaQ2?

[Kris Dahl <krislists@xxxxxxxxxxxxx>]

> finding a solution that will allow me to do that.  In fact, I'd
> even be interested in making the secondary an *exact* duplicate
> of the primary, ie. same IP address for primary ethernet
> interface, etc.  So that if the primary one dies I just move it's
> ethernet connection to the secondary and it looks like the same
> box to the world on the internet.

There are problems with having the machine configured *exactly* the same as
the other one: i.e. how will data get trasnfered (they need seperate private
IP addresses), one needs to know that it is the 'slave', etc.

What you are talking about is load balancing for redundancy as well as
performance.

There are several ways to accomplish this: Linux Virtual Server is one
software approach.  Foundry networks, F5, Cisco and VA all make hardware
solutions.

> I have been reviewing backup solutions, because quite frankly the
> data on the machines are more important than the machines
> themselves, right?  If they take a rather physical death, ie.
> hard drive goes out, cobalt users need a quick and efficient way
> to get all of their customers back on line.  A two month
> magnoscopic intrusive rebuilding of the data from the drive is
> not the way this needs to happen.  I'm sure that there are plenty
> of other RaQ2 and even RaQ1 owners that have come up with clever
> ways to get the data off of one machine and on to another so they
> can be back online in a matter of hours, not days.

What you are talking about here is the need for the ability to survive a
single disk failure.  RAID is your solution.  Hell if you do it right you
can have several disks fail--it just depends on how much you want to spend.
It is important, IMO, that your critical machines stay up all the time, and
that means using RAID *with* a tape back up solution for catastrophes.

The Raq4 is sounds like it is more what you want, but I have been critical
of it.  Cobalt is talking about the cost savings of the IDE and software
raid that they are using on the machine--yet it costs same as a full-out
RAID 5 (in hardware) on 3 18.2 GB 10K SCSI Disks.  So I guess I could care
less if it is more cost-effective if the only people that are saving money
is Cobalt (i.e. not the person buying the product).

> I've looked into rsync, direct copy via NFS mount, Samba
> equivalent copy, BRU from Enhanced Software Technologies, but I
> feel that there is a better over all way of doing this.  Any help
> in this matter will be greatly appreciated.

I would look at a couple things on a scale of least expensive to most.

1) Use rsync to sync up the two Raqs.  Exclude certain files that need to be
unique to the machine--that would include the
/etc/sysconfig/network-scripts/eth1* for the private interface.  I don't
recommend this solution

2) Get a Raq4 or similar system with RAID

3) Invest in a load balancing / clustering solution from like F5, Cisco, VA,
etc.  While not inexpensive (actually the VA is *very* cost effective) this
is really the only way to go.

-k