Huge backup system - need advice!

[anths]

First off - I know there is already a thread like this but these questions are pertaining to a system not intended for personal use as well as quite a bit bigger so I felt it would probably be easier to create a new thread rather than highjack the other one!

I am currently building a massive backup unit for my college radio station. They are going to digital broadcasting and therefor want to have all their music on a central computer to stream from so they can do away with cds most of the time. I do need some help on a few issues though guys.

1: I need a case bigger than the 5u cases with 24 hot swappable bays. I am thinking a 7u case with as many hot swappable bays as possible. I am planning on using 200gb drives for now since they seem to be cheapest per GB (I am going seagate - not cheap drive but cheapest per GB). All drives will be SATA. Could you recommend a good 7u rackmount case with, obviously, 3 solid redundant power supplies?

2: I need 4 RAID cards that can work together to form 1 Raid array. This array will be on the order of 6-8 Terabytes. I would ideally like a RAID-6 array to save a lot of hassle if anything ever happens but would be willing to go with RAID-5 if necessary. PCI-X or PCI-E is fine, I will get a motherboard according to the cards.

3: How do I back this thing up?! I know a RAID-6 array would give me some peace of mind but still.... losing 6TB and weeks of ripping/encoding would drive me insane! I have no idea how to backup something of this proportion though - I guess a few hundred DVD's could do the job but that is just ridiculous.

If you could help me with these three problems, I will be well on my way to building (and documenting) this system. Don't you worry, I will take enough pictures of this thing to satisfy all your storage pron needs!

In case anyone cares - the music will be stored in FLAC to save space and keep the quality of WAV.

Anthony

[ashmedai]

6-8 TB @ 200 GB per drive in RAID 5 would be what, 31-41 drives? At the low end of that you could do 4xRAIDCore 8-channel cards. You'd need 4x 12-channel to hit the high end though and they don't make a 12-channel model AFAIK. Areca has a few that might suit you and their stuff is very good, if at the high end cost-wise.

Backup on large arrays is a bitch, you're kinda stuck with tape or praying you're not there any more when something goes wrong.

[draksia]

With the need for that much capacity and real raid conrollers I would highly recomend you think about external storage.

As for one raid array you are basically out of look no current file systems readily support greater then 4TB LUN's. There storage software that will allow you to span multiple volumes.


Also from working with it at work raid6 has some serious performance issues when compared to raid50. As well as very limited support. It is becoming more popular and will likely improve in performance and support in the near future.

I would personally recomend 2 nStor 4700S sata to scsi enclosures each one is 2U 12 drive box with reduant powersupplies and its own raid controller. Fill with 300gb sata drives which offer the best comprimise of capacity and number right now. Then add a 1U server to complete the package. The whole thing would be 5U and cost roughly about $9000 when you are all said and done.

I would definetly go with a proper and correctly engineered external enclosure. You will be much happier in the long run.

[anths]

In regards to performance of the RAID array. It really doesn't matter. It is only going to be streaming 1 song at a time to 1 computer so 150+ MB/sec isn't even close to necessary. I am going to look into the external enclosures - I didn't even think of it to be honest.

[ashmedai]

I don't suppose they considered something simpler like a disc changer? It'd be alot less pricey.

[DougLite]

1) I agree that 200GB drives aren't going to get it done. 300GB+ drives are worth the premium here to reduce the number of spindles (and chance of failure). Lower rackspace requirements, lower cooling requirements, etc. Be sure to get one of the high density platter drives - Hitachi does have a 400GB drive, but it's on 5 platters - more heat and power consumption, also less reliable mechanics with five platters. 400GB Seagate 7200.8 or 300GB Maxtor MaxLine III is your best bet here, IMO. They are both 3 platter drives. 8 TB is 21 400GB Seagates in RAID-5 or 28 300GB MaxLineIII's. 24 MLIII's net you 6.9TB. in one RAID-5 array.

2) Many RAID controllers have a cap on array size of 2TB, although other [H]ers have al rger knowledge here than I

3) 6-8TB is over 1000 single layer DVDs, and barely fits into 1000 DL DVDs. Google for tape caroseuls.

I will add that I don't think one big array is all that practical here - I get the feeling that it will spend as much time rebuilding as it is fully available. External storage seems to be a really good idea. Also - 6-8TB seems like overkill even for this much music...Even if they were WAV files at 11MB/minute. FLAC looks to reduce this by about another 40%, to about 6MB/minute. 6MB/minutes goes into 6TB quite nicely - 1 million minutes of audio (using decimal TB) or 250,000 four minute songs. I remember amassing 20,000 MP3s, and thought there wasn't much else out there - that I liked. ;)

[unhappy_mage]

For the cheapness end of things, have you considered getting a bunch of 8-port sata controllers (http://www.thenerds.net/productpage.asp?un=193684&s=1) with no hardware raid? Then put them in a linux box, use software raid+LVM, and save. If you need capacity but not necessarily speed, this will deliver. And it's no sluggard either - you can get 30-50MB/s out of them. Not blazing fast, but for delivering a single stream of flac, it's definite overkill.

That's my suggestion, anyways, and it's fairly futureproof IMO. You can just buy more sata controllers if you run out of space, and not worry about expansion problems - just make a new array and expand the LVM onto it.
http://www.mentallyretired.com/h3/index.cfm/u_47426 (http://folding.extremeoverclocking.com/user_summary.php?u=47426)

[Order]

Can't get much better than this bastard right here: http://www.rackmountpro.com/productsearch.php?catid=189

[anths]

Also, about the disc changer idea...

This radio station has around 12,000 cd's currently and they also want room to expand over the next years. with with 400disc changers that would be 300 of them daisy chained and then there would be no order once you started adding additional cds.

[valve1138]

www.servercase.com has some gigantic server cases with tons of drive bays. I think they have an 8u with something like 40 bays.