SATA RAID suggestions?

[lordsmurf]

I believe my motherboard has RAID, but I don't think I want to screw around with it. It has two drives attached, and everything works fine as-is.

I need to add 1TB of space, preferably internal, and will be getting a Seagate 1TB 7200rpm (32MB buffer) SATA drive.

Rather than manually back up, I think I'd like to do a RAID mirror, buy two of the Seagates. And to not mess with the motherboard, I think I'd like to do it via a controller card.

I lean toward Promise, but I don't know much about SATA RAID (aside from the ins and outs of using RAID at all).

The computer is a Dell XPS 600.

What concerns should I have? Anything I should realize about this setup?
What brands of cards are suggested, or what sort of features are required on such a card?

If one of the drives ever dies, I can still access the non-dead drive, correct? If that happens (hope not) I'll probably have to replace both drives with something new (as I believe they must be identical, no?).

Thoughts?

[Soopafresh]

Yeah, you're right. It's possible the controller on your mobo supports Raid1 (which is what you'll want for hardware mirroring). But if you prefer to use a controller card, Promise makes some good ones, as does adaptec. I'd lean towards promise, though. You can set up the mirroring during your computer boot process - typically CTRL-A to bring up the controller card bios setup.

And yes, your drives should be identical for hardware mirroring. Check the serial numbers on the drives and make sure they're not close - you don't want two drives both from a bad batch (happened to me with two drives - sequential serial numbers).

[TBoneit]

Normally you do not need to match the drives in a mirror however a couple of caveats:

The mirror will only be as large as the smallest drive
The mirror will not be faster than the slowest drive.
A mirrored drive will be slower than a unmirrored drive. It will be safer from drive failure.
Mirroring will not prevent oopsies where you delete something nor will it prevent Virus damage.
Mirroring is not instead of making Backups it is used along with backups.
Mirroring is to allow the drive to continue in service if one of the drives fail. If one drive fails it will still be available and the monitoring software should prompt you to replace the failed drive.
Mirroring is really only necessary if teh computer can not be offline.

Look for a Hot swap mirroring controller that will allow the computer to remain in service while the drive is changed and the mirror is rebuilt so the compuuter can stay online. If staying online isn't needed think periodic backups instead.

Asus makes a server system that comes with case & Mobo and Power supply and 4 hot swap bays for SATA drives. Ther last one I did was a Xeon processor and two 80Gb drives mirrored. Reliability was the issue as it was server not drive space. I belive it was under $1500... Something like the towers on this page if interested. http://www.asus.com/products.aspx?l1=9&l2=40

If the drives had to be matched mirroring would be a useless technology as drives are discontinued all the time.
We have a commercial customer that has mirrored drives. He started with 40 Gb WDs. As they die we replace them with 80Gb WDs and rebuild the mirror. The mirror is no faster than before since the 40Gbs are 5400 and the mirrored drive is still 40Gb and the customer is happy they don't have to replace both drives. If anybody is saying so small? They only have about 8Gb used on any of the machines.

[lordsmurf]

The mirror is wanted for storage of raw photos, up to 1TB worth at any given time. I have neither the time nor the funds to back it up all the time. How much will a mirror slow down the drive? Are we talking the 7200rpm drives will act like 5400rpm drives?

[Soopafresh]

No, it's about a 10% performance hit, but who cares if you're just storing images on it.

[lordsmurf]

I was afraid to goof with the computer motherboard (I cannot risk messing up the existing drives, nor would I want the current ones mirrored), I'd just assume add a card to add some drive. I think I'll go down the Promise route. There's a Promise card for about $75 on newegg.com. Does that look to be a good one?

A pair of Seagates for mirroring.

A 10% hit basically puts it back to an IDE speed performance. Not an issue. It's mostly for image storage, although I will be editing the NEF's off the drive directly, saving the edited versions to a server (which has automated tape backup).

[Soopafresh]

http://www.newegg.com/Product/Product.aspx?Item=N82E16816102060 for <$60 is fine

If you don't have fans blowing on the drives, consider something like this:


http://www.newegg.com/Product/Product.aspx?Item=N82E16835200032

[rallynavvie]

For 1TB I'd even recommend one of those external SATA bays that have 2 drive slots and a RAID controller. You can get them with an eSATA connection to run to a free SATA port on your current system (with an adapter plate for the back of the PC) or to a simple SATA controller (HBA?) in a PCI slot. The nice thing about having the mirrored array external is the ability to turn it off when not needed and move it to other systems (especially if your current PC should die a horrible and dramatic death as has happened to me in the past). Moving an existing mirrored array to another system is possible in such a case but sometimes it won't work even with the same controller being used to manage the mirror.

[TooLFooL]

why waste $75 on a controller when your motherboard has full support already? just plug in the drives, turn on RAID in the bios, and go from there.. you wont mess anything up!

[rallynavvie]

Because then you absolutely can't take it with you if the system goes boink. Also I think he's using the onboard channels for single drives already.

[redwudz]

I use two PROMISE SATA300 TX4 PCI SATA II Controller Cards for eight 320GB WD drives in one of my video servers. No RAID, though. They have been working with no problems for about a year. I've haven't seen a cooling problem either, and the drives are about 1/4" apart. SATA drives seem to run cooler than the equivalent PATA drives. The case does have a front intake fan that moves some air over the drives.

An external case does have some advantages, independent power supply and better cooling, and of course, a bit easier to set up if your computer case is cramped. You can get SATA controller cards with external SATA or eSATA connectors, or just use an internal card and a SATA PCI slot adapter from the internal card. SATA can use up to 1 meter cables, eSATA almost twice that. Just something to consider.