Building a RAID server???

[squirrellydw]

Can someone help me build a RAID server?  i would like to use an old PC, what else do I need, OS, raid card, drives??

I would like recommendations for a raid card, and the OS has to be windows and anything else I need.

[XyloSesame]

What's your intended use for the array?

[Samstag]

It would help a lot if you explain what sort of raid configuration you're aiming for and what type of drives you'll use.  Also as XyloSesame asked, it's somewhat important to know how you'll use the machine.

If you're going to use an old PC (and especially if you're only going to use it as a simple network-attached storage system) I don't see any reason to spend money on dedicated raid hardware.  Windows XP and Linux can both do software raid and if the CPU and storage aren't going to be doing a lot of heavy simultaneous jobs then performance will be good for very little cost.

My raid 5 setup is based on cheap PC hardware and Linux.  I've got a pair of 4-port SATA adaptors that cost about $15 each to handle 8 250 gig drives.  So you're talking about $15-30 plus the cost of disks if your PC has 2 open PCI slots and a power supply that can handle the load.

You might also want to invest in some gigbit ethernet cards and a switch if you're going to do heavy transferring.

[squirrellydw]

I plan on using RAID 5 and Hitachi SATA drives.   I would like to use it for backup as well as accessing my music from two computers at the same time.  Also accessing my photos now and then and store my Ripped DVDs on it and access them to watch on TV.  I guess it will be used mainly as a media server but I want to use it also to back up some data.  It needs to be able to connect to both windows and Mac.  I would prefer to have hardware RAID but not sure what the benefit to it is.  I just want to make sure if a drive dies that I can replace it and not lose the data.  I will probably start out with 3 drives and add 2 more in the future.  I have access to to win2000 and XP Pro, will they work or should I use something else, has to be windows based since I don't know anything about Linux so please don't suggest that.

oh, the PC is a P3 something, don't remember the exact specs.  I will build a new one after I have it setup and working and have more money

Thanks

[Samstag]

The advantage of hardware raid is that when you're using raid 5 it requires parity calculations for every read and write.  Normally you'd want hardware, but if this PC is doing nothing but move files from disk to network and back, you might as well use the CPU to take care of that.  It's been a long time since  looked at raid cards but I doubt you'll find one that'll take care of your needs for under $200.  Or buy one of these for $22 (or shop around for cheaper).  Note that those are 150M/s Sata I adaptors, which will suit your needs just fine.  Unless you can get SATA II cards for the same price they're not likely to be a signifigant upgrade.  Spend the money on the drives and get some nice big ones.

Win XP can do raid 5 but it requires a small hack.  I've never done it but I'm told it's fairly simple.  My experience is all with linux.

[boykster]

One key thing I noticed you'd like is array expansion (start with 3 drives, add more later).  That's not very common in either software or hardware raid.  Its becoming more common in hardware RAID cards though.

I have 3 RAID5 arrays built using older (7000 series) 3ware cards.  2 are 8 drive arrays and 1 is a 4 drive array.  I've had great experience with the 3ware series of PATA cards, but they don't do online array expansion.  If you want to grow an array, you have to transfer the data off the array, add the drive, re-create the new array, and then transfer the data back.

You might consider unRaid as well.....

http://www.lime-technology.com/

[squirrellydw]

anyone recommend a raid card for sata2 drives?

[XyloSesame]

anyone recommend a raid card for sata2 drives?

Check out http://www.3ware.com - I've not personally used 'em, but know a few folks who swear by 'em.

[Samstag]

anyone recommend a raid card for sata2 drives?

Check out http://www.3ware.com - I've not personally used 'em, but know a few folks who swear by 'em.

I like Promise cards, but haven't used any of their Sata II or RAID 5 cards.  I'm using a 4-port Sata I that does 0, 1, or 0+1 that I like a lot.

[patrickl]

I had a RAID card break down on me. I didn't have a replacement so it was highly unpleasant. Imagine sitting there with your redundant array and no way to read it. Luckily I had a backup, but still

That's what I like about the Infrant ReadyNAS. The disks can be mounted in a UNIX environment and will (should) be readable even without the hardware.

Actually for most applications I now use simple mirroring. Slightly more expensive, but never a problem when the hardware breaks.  I think many motherboards support this standard. Even my notebook does it.

[boykster]

Unless you run a redundant array of arrays (overkill for home usage) you will always be subject to a single point of failure taking the data offline - the controller card.

I like 3ware cards specificially because the array data/format is not card specific.  An array created on an older 7000-8 card can be read on a newer 7506-8 card (etc) as long as the card supports that drive type (ie sata or pata).  I have 3 arrays built with 3ware cards, and I keep a spare 8 port card handy in case I need it.

Mirroring using the onboard controller is fine, as long as the onboard controller doesn't fail.  What do you do then?

RAID is not a failsafe for catastrophic data loss, just a technique to try to ensure data availability and uptime. 

[patrickl]

Mirroring using the onboard controller is fine, as long as the onboard controller doesn't fail.  What do you do then?

Stick the disk(s) in another computer. Heck it would even work in a simple external housing and these are dirt cheap.

[boykster]

Mirroring using the onboard controller is fine, as long as the onboard controller doesn't fail.  What do you do then?

Stick the disk(s) in another computer. Heck it would even work in a simple external housing and these are dirt cheap.

Not necessarily; in fact a colleague of mine just had a 2 drive RAID1 mirror array die on him and he had to jump through hoops to get the data off.  He had to buy an add-in card with the identical chipset and force the array to be recognized.  Not all 'mirrored' volumes are just plain old regular volumes....

It is possible to use a bit for bit volume copy program ('dd' in linux for example) to backup a dying RAID drive however...

[patrickl]

Not all 'mirrored' volumes are just plain old regular volumes....

Well my point was that I use mirroring hardware that does simply mirror two drives so that each drive will work outside of the RAID 1 array as a regular disk. Also that the RAID 5 solution that I use has disks that can be mounted and used in FreeBSD or Linux as an aray and the seperate disks contain mostly complete files. ie I'm not dependent on specific hardware parts to be able to access my drives within a reasonable time.

To be honest I hadn't considered that mirroring hardware would actually not simply mirror a complete disk. That sounds overly complex. I assumed they basically just duplicated the drive write commands to both disks.

[Samstag]

When I built my most recent PC I thought onboard RAID 5 sounded like an excellent idea, but it's not.  It's a proprietary implementation and of course the mother board went out after a couple of months.  From now on I'll stick to my linux RAIDs.  No matter which single piece of hardware dies, I can be back up in the time it takes to swap parts and/or rebuild a new drive.

It's also slow as molasses on my Asus board.  Never again.