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raid set up recommendation...

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Joshua Burket
raid set up recommendation...
on Apr 13, 2010 at 3:35:02 pm

I recently purchased the following equipment:

Mac Pro:
Quad Core 2.26
Mac Pro RAID Card (is this card as bad as all of the rumors say it is?)
(4) 1TB internal hard drives
(2) 18x Super Drives

Promise SmartStor DS4600 with (4) 1TB swappable drives.

I also have (4) 1TB external G-Techs (which I had for an earlier project) that I was thinking about using solely for media back up in lieu of not having my MINIDV tapes cloned. I have about 125 hours of footage on MINIDV.

I am new to the RAID world, so with the above set up how would you go about configuring a RAID set up for media/project protection.

NOTE: I am installing a single eSATA port in my Mac Pro that I plan to plug into where the 2nd optical drive is plugged into. This way I can connect the Promise SmartStor DS4600 via eSATA to the Mac Pro.

Any advice would be greatly appreciated as this is my first large project with so much footage to store.

Josh


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Dave Klee
Re: raid set up recommendation...
on Apr 16, 2010 at 5:31:04 pm

Hey Josh, lots of ways to go with this, but you probably want to do a lot of RAID-5. RAID-5 gives you a mix of protection and speed -- one drive can fail out of your RAID set with no data loss, but data is split up across all the drives in the RAID to make access quicker.

Personally, I always setup editing computers with a single system drive that is NOT in a RAID. So, with your Mac Pro with four drives inside and a RAID card, I'd recommend the following:

Drive 1 = System drive where your operating system is installed along with all your software
Drives 2-4 = RAID5 set that you would use for media files, capture scratch and rendering

If you have big problems with your computer some day, or want to do a major upgrade in the future and reformat, it's nice to have the flexibility to keep your system drive with all your applications completely separate from your documents and media.

Are those G-Tech disks single drive enclosures? If so, I'd use one to backup your system drive if you have a problem (once you get your computer working the way you want it). Carbon Copy Cloner is a great little (free) drive backup utility you might already know about: http://www.bombich.com/

As for that four-disk external Promise RAID, I haven't used one of them before. It should be plenty fast enough to edit with, and for Mini DV, you don't even have to mess with eSATA if you don't want to. Firewire can do Mini DV just fine. However, if you're capturing from Mini DV over firewire, it's generally best to capture to a non-firewire drive (the built-in firewire ports don't like to handle a video device AND anything else at the same time). So, you could capture via eSATA to the Promise or to your internal RAID from a firewire source.

For your Mini DV tape backup, I wouldn't worry about it too much. If you do a good job of logging and capturing (giving all your tapes clear numbers so you could re-capture from them if necessary), then keep those tapes in a safe place, they'll last for quite a while. If you figure that your tapes will last at least 8-12 years (depends on a lot of conditions), and a hard drive can easily die before that, your ultimate backup for everything right now is tape.

Sounds like you'll have plenty of space for this project. 125 hours of Mini DV should be around 1.5TB. I'd lean toward putting everything for this project on your Promise RAID because it'll have a little more space and be slightly portable than your internal RAID (you could plug it into another computer if you needed to). But, the ultimate choice is up to you about where things go.

My only real advice is to do a great job of logging your footage and stay as organized as you can. With a project this big, you'll thank yourself later.

Good luck!



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Joshua Burket
Re: raid set up recommendation...
on Apr 16, 2010 at 7:11:35 pm

David - thanks so much for your advice. you're so right there are many ways to set this up and I think I've heard them all! But in all honesty your set up may be the best of all.

Thanks so much for giving me your advice - it was well worth the wait! Have a great weekend.

Josh


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Joshua Burket
Re: raid set up recommendation...
on Apr 16, 2010 at 8:23:27 pm

Dave:

I already thanked you in my previous post - but I noticed one fatal flaw in my original posting that may or may not make a major difference in the RAID set up you recommended.

I inadvertently typed in 125 hours of footage when I meant to type 225 hours of footage. Does this make a major difference in the set up you recommended to me in your reply? Sorry for this last minute wrench - I just thought I'd throw that in. Thanks in advance Dave.

Josh


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Dave Klee
Re: raid set up recommendation...
on Apr 16, 2010 at 9:28:49 pm

Hey Josh, well that makes things a little more interesting, but you should still be okay.

Let's say you format those three disks inside your Mac Pro as a RAID-5 set. That'll give you roughly 1.8TB.

If you format that whole Promise RAID as RAID-5, you'll get 2.7TB or so. Those are both rough guesses.

Essentially, I'm taking the raw capacity of your drives in each RAID set (3 X 1TB = 3TB internal, 4 X 1TB = 4TB in the Promise), subtracting one drive because RAID-5 essentially removes a whole drive for backup, and then subtracting 10% for overhead (because no hard drive gives you the full capacity it SAYS it does). So, your internal RAID will be (2 X 1TB) - 10% = 1.8TB, and your Promise RAID will be (3 X 1TB) - 10% = 2.7TB. That overhead number can be higher or lower depending on a few things, but it's closeish.

One thing to keep in mind is that no RAID (or hard drive, for that matter) likes to get totally full. You want to keep things below 80-85% if you can. Nothing will blow up, but performance goes down.

So, if you've got 225 hours of Mini DV, you're getting close to filling your Promise as a RAID-5. There's an alright storage calculator here that shows you at 2.41TB for that much footage: http://www.digitalrebellion.com/footage_calc.htm?format=dv_ntsc_f&frame_rat...

Best thing I could tell you is to pair down your footage on capture. When dealing with big projects, it can be very tempting to digitize everything and sort it out in your editing software (because it's so much quicker and easier to scrub through QuickTime files than raw tapes). But, I would imagine that in 225 hours of footage, you've got at least some stuff you won't use. If that's true, try to leave all the outtakes and stuff that's clearly not helpful on the tape -- that will cut down the space you need to capture, and might make that Promise RAID more than enough.

But, if you really do need to capture every moment of that footage, your Promise could probably handle most of it. The last 50 hours or so you could capture to your internal RAID, and then use the internal RAID for rendering during your edit. I don't like to split a single project across multiple devices like that, but if you really need the space, it should be fine.

Your other option would be to completely maximize your space and go to RAID-0 on everything -- which gives you more space but if any drive within your RAID set fails, all your footage is lost. I don't like it. I think you're better off with RAID-5 and trying to split your footage across that Promise and your internal RAID if you truly need to digitize everything.

So, this is a really long way of saying I'd still recommend the same general setup -- just be more careful about what you digitize. I hope that's helpful, and good luck with it all! Have a great weekend!



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Joshua Burket
Re: raid set up recommendation...
on Apr 19, 2010 at 5:01:31 pm

Dave - thanks so much for all of this information. I am putting it ALL to use as I set up my RAIDs today. Thanks again for putting all of the time and your patience into your responses - you a very appreciated!

josh : )


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