I am about to purchase a new server, I am looking to put SCSI hard drives in it, however the required motherboard does not have onboard support for SCSI raid and $900 for a scsi raid card is a bit much.

So the question is how reliable is the software raid of Linux? Has anyone ever had a bad experience with it? inaccurate mirroring etc.

I wouldn't recommend doing software raid. Maybe you should be looking at SATA hard drives and a raid card for them (should be significantly cheaper than SCSI).

well the board does have built in hardware raid for SATA, so that is not a problem. I was mainly looking for scsi because of the performance increase.

using software raid you will lose that performance not to mention stability of mirroring. With software raid it is only duplicating information while the software is running that means every time you restart the system the raid sets have to resync. With hardware raid it starts the raid right when the hard drives spin up.

Sata would be the better solution if you cannot afford SCSI

You can compare the stats here: http://storagereview.com/

Also, you should first decide if it's even needed. Maybe your server will benefit more from added RAM?

$900? If you only need mirroring, you can get a SCSI RAID1 card for $200.

Had no problems with software RAID on a desktop level machine but for servers definitly hardware, ideally with hot swap

If you're going with SCSI, a hardware RAID card should be faster than software RAID but if you go with SATA you will be using software even though you have SATA RAID on your motherboard because most SATA RAID card are just some BIOS support for RAID and a driver, the computer will be doing the actual RAID.

But of course for a server I would recommend SCSI with hardware RAID if you can afford it but if you already have the server and the SCSI hard drive you can test software RAID before getting a hardware RAID card.

I used software raid with some Ultra-SCSI drives on my old poweredge. It worked out very well for a small test / development server. I think that if you budget will not allow a hardware raid card, go for the software raid.

Greetings:

We've used both software raid and hardware raid over the past 10 years in business.

We've found that software RAID can work well IF (and here is the underlying problem) the hardware is rock solid.

Certain types of crashes can corrupt the software portion of the RAID thereby making data on both hard drives inaccessible.

We've found hardware RAID works the best.

Thank you.

Bottom line stay away from software RAID. I call this poor mans RAID. If you like your customers get hardware RAID. I think most have given you this recommendation too.

Originally posted by bqinternet
$900? If you only need mirroring, you can get a SCSI RAID1 card for $200.

hmm perhaps could you make a recommendation on a card like that? also wouldnt a pci-x riser be needed?

thanks everyone for your input.

Originally posted by Forbidden
If you're going with SCSI, a hardware RAID card should be faster than software RAID but if you go with SATA you will be using software even though you have SATA RAID on your motherboard because most SATA RAID card are just some BIOS support for RAID and a driver, the computer will be doing the actual RAID.

But of course for a server I would recommend SCSI with hardware RAID if you can afford it but if you already have the server and the SCSI hard drive you can test software RAID before getting a hardware RAID card.

You can have software or hardware sata raid just like scsi. However many sata raid controllers have an "optional" software tool that you can use to control the hardware from within the OS.

an example: http://epox.com/USA/product.asp?id=EP-8HDA5plus
for instance allows you to controll the raid sets directly from the raid bios and will rebuild without loading any software.

Originally posted by dynamicnet
Greetings:

We've used both software raid and hardware raid over the past 10 years in business.

We've found that software RAID can work well IF (and here is the underlying problem) the hardware is rock solid.

Certain types of crashes can corrupt the software portion of the RAID thereby making data on both hard drives inaccessible.

We've found hardware RAID works the best.

Thank you.

This is exactly the problem and why software raid should not be used in servers. For dev systems it's great alterative solution.

Originally posted by bqinternet
$900? If you only need mirroring, you can get a SCSI RAID1 card for $200.

I did some looking around is this what you are talking about?

http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=132617

well the board does have built in hardware raid for SATA, so that is not a problem


inbuilt RAID on the motherboard is basically Software RAID as well.