Can I add an external Raid 1 HD to an existing system?

[ArtBest]

I have a Dell Optiplex GX620 Small Form Factor PC in my office. Because it's the small case, it only has one HD slot, and has a single SATA 2.0 channel supporting up to two devices. It is running XP Professional. And it has an open PCI Express 1.0a slot available.

What would be the best way to add a second, external, disk to run in a Raid 1 setup? If I add a PCIe Raid controller card, will it be necessary to reinstall the operating system, or can the current disk be switched over to the new controller and Raid implemented without reinstalling the OS? In order to have a RAID, am I correct in assuming that both drives must run off the same RAID controller?

I don't know know if the onboard SATA controller can run a RAID, but I assume it cannot. So my assumption is that I would have to add a RAID controller card, and have that run both the internal drive and an external eSATA drive. Do I need to reformat the internal drive and reinstall the OS as part of this process?

As an alternative, anyone have any good suggestions for alternative ways of having real-time data backup? I think that some IOmega USB drives come with software that does that, but I'm not familiar with it or how well it works.

Thanks for any help.

[glc]

Real time or RAID 1 is not the best way to do it, because any OS/software/data corruption will simply corrupt the backup too. I'd get a standard USB external drive and software that will do timed or manual backups.

[ArtBest]

I am more concerned about a disk failure than software corruption. I would like to do disk mirroring.

And of course that and periodic backups are not mutually exclusive and both will be used.

[glc]

You will need a controller card to do RAID 1. Both drives must be on it.

[ArtBest]

Thanks.

Will that require reformatting the bootdrive and reinstalling the OS? Or can I switch the boot from the on-board controller to the new controller without upsetting the apple cart?

[glc]

Will that require reformatting the bootdrive and reinstalling the OS?

Yes, and you will also need a floppy drive.