Which RAID would you recommend?

[roofles]

Hi I'm thinking about setting up a small file server for a network and wanted to set up a RAID. Just had a few questions, I tried googling but apparently the term RAID is a popular word and I didn't get exactly the info I needed for my setup. Basically it'll be a repository for anime, probably more reading that writing of episodes (each about 150-200MB) . Now, since I have a limited budget Im planning to set up RAID 3 or RAID 5 since it seems to be more efficient than RAID1 or 0+1 though at the price of performance.

Just have 3 questions:

1. Am I way off base and should I stick with RAID 1/ 0+1?

2. What card would you recommend for this setup, or are there any motherboards that have onboard RAID controllers that seem to be reliable? (obviously its not mission critical but I would like to be able to recover from disk failures, time constraints are not a factor at all

3. In a RAID3 or RAID5 setup, will my disks die faster? It seems to me with all the striping across drives, each individual disk's life would be shorter it's just that you have the advantage of rebuilding the data. Any experience that you guys have with this would be awesome, I'd rather stick with RAID1 and not have to replace drives as often (we're all kind of chipping in for this since we all have small form factor cases and would like to have one place store everything).

thanks.

 

[mechBgon]

Big picture: if you have a 100Mbit network like many small outfits do, the data's not going anywhere faster than 8-10MB/sec, since 100Mbit = 12.5MB/sec peak (theoretically) minus overhead. So the bottleneck in raw throughput might easily end up being the network.

For simple transportability of the data at a low cost, consider just software-mirroring the storage drives in pairs. You're set free from being tied to a particular controller. I'd undercut the total capacity of the drives a smidgen when creating partitions/volumes, so if you have to swap in a slightly-lower-capacity drive to fix a broken mirror a couple years from now, you don't find yourself a few megabytes shy due to slightly-different capacities between models.

Just a thought

 

[rforum]

A couple links to help you. I administered a small 15 person network where the server was used mainly for e-mail (Exchange Server) storage - mirroring worked fine.

http://www.gtweb.net/RAID_desc.html

http://www.storagereview.com/g...000/ref/hdd/perf/raid/

 

[roofles]

Thanks for the replies guys, just to give you an idea, I don't expect it to grow much more beyond 500GB or so... perhaps 2 250GB drives mirrored would be the simplest thing? (least amount of headaches too)

mechBgon, about undercutting the capacity, would that really be a concern since with technology, HDs tend to get bigger anyway, would it really be worth it to not use all the space possible on my HD or did I misunderstand you? (i am just trying to clear some things up, I am not attacking your position or anything).

 

[rforum]

You know 2 mirrored 250GB drives gives you 250GB of space to work with. Raid 0 with two 250GB dirves would give you 500GB but with no fault tolerance.

 

[roofles]

woops i typed too fast i meant two sets of 250gb mirrored drives. duh me, please forgive me

 

[mechBgon]

I was just thinking back to when a drive failed in a two-disk mirror at work. They were SCSI, and SCSI drives generally come in only a few capacities (9GB, 18GB, 36GB, 73GB, 147GB). It would be a major pain to have to buy the next-bigger SCSI drive just to get an extra 40 megabytes. But as you say, ATA drives keep getting incrementally bigger, so maybe it's not that big of a pitfall there

 

[uOpt]

I just posted my RAID thoughts here:

http://forums.anandtech.com/me...ey=y&keyword1=raid

I'm somewhat hesitant to say, but if you set up a RAID array and don't know enough about RAID, that could lead to very bad accidents. If you check this forum you see that some bad stuff happened to quite some people. You don't want to have "bad stuff" happen to a company which could sue you if you don't have enough knowledge leap to make up an excuse they can't see through.

If you want a failsafe solution without much knowledge overhead I would recommend getting a SCSI controller and then a black box which is doing RAID5 inside it and just blinks at you with a few LEDs when it wants its diapers changed errr a disk replaced.

 

[tynopik]

i like raid 1 because it's very foolproof

if the array gets messed up, just pull out one of the drives and connect it to any old controller and pull data off

if your RAID5 gets messed up, you're screwed (and i've read lots of horror stories of people messing up their raid5)

 

[classy]

But you something that is really overlooked and that's Intel's matrix raid. It really is a nice feature giving you a quasi raid 5 but using only 2 drives. The only draw back is expensive ddr2 and Intel is behind AMD right now. But it is very nice feature. If your going to build file server maybe this might fit your budget. Matrix Raid

 

[Stangs55]

RAID 1+0 would be nice.

 

[Farvacola]

Go for raid 1, it seems to me thats all you need for such a small network.

 

[uOpt]

Originally posted by: tynopik
i like raid 1 because it's very foolproof

if the array gets messed up, just pull out one of the drives and connect it to any old controller and pull data off

if your RAID5 gets messed up, you're screwed (and i've read lots of horror stories of people messing up their raid5)

The latest blowup thread on this forum was for a RAID-1, shredded by the stupid controller detecting a messed up drive combo back to the OS which "checked" the filesystem, eliminating most files.

However, there is much truth in your post.

You should understand what RAID-5 does if you want to run it, so that you can reinsert the drives properly. As much as a bash Windows, I would have lost my RAID-5 arrarys on my Maxtor incident if I wouldn't have been able to figure out that Fedora Core 2's startup scripts suck (and how to repair them) and that of the two RAID userland packages for Linux the raidtools are trash and mdadm is the right one for serious work.

Having said this, even in RAID-1 you can have a hardware/software misunderstanding like the above or you can screw up hooking a new drive in.

If this is a very serious thing I still say either learn RAID in and out or buy a black box on a SCSI bus.

 

[roofles]

Thanks for all the replies, I think I'll stick to RAID1, it seems the easiest/most foolproof array to maintain and should suit my needs perfectly. This is more of a project between me and some friends, so I'm not worried about getting sued or anything ( I hope!)

can anyone recommend a raid controller that is affordable/reliable? And are onboard raid controllers any good ? Thanks.

 

[SadisticOne]

Onboard RAID controllers will probably suit you fine.

http://www.techreport.com/revi...set-raid/index.x?pg=28

If you want reasonably priced SATA RAID on a PCI card, look at Promise controllers. Bear in mind that a PCI card will limit bandwidth, but a regular RAID1 should affect that in the least. Some onboard RAID solutions offer potentially more bandwidth in some situations.

 

[KBtn]

For something small, a good a mirrored array is usually just fine. Another simple solution would be backup software and an external firewire or usb data drive.