RAID Maintnenance?

Hi all:

I am running a homemade 8 SATA drive RAID 0 on a G5 dual 2.3 GHz. The RAID used four internal and four external Western Caviar 320 HDDs. I normally run MacJanitor and Repair Permissions on my system drive. The RAID is giving me good results, I get sustained rates of 480 MB per second throughput, it never has dropped frames and we have functioned with every size and kind of HD video you can think of.

I have been running the RAID for about a year and so far, knock on wood, it's been bulletproof. However, my RAID is contantly filled up with different sorts of projects of various sizes. Our workflow is to lay off all of our P2 cards to the RAID, then we lay off the the P2 media to an AJ-HD1400A for archiving. I have never done any maintenance to my RAID and I have read several various conflicting opinions about whether or not you should do any sort of maintenance to a RAID, especially when it is contantly full of media that I have nowhere else to move it to.

What do the RAID experienced minds here think about RAID maintenance? What should I be doing, if anything? Aren't my drives becoming totally fragmented because of all of the loading and unloading of media?

Any advice is appreciated.

Thanks,

Dan

I don't think there is a "RAID maintenance" other than wiping the dust off the case every so often. Essentially its OSX maintenance which is already what you are doing with MacJanitor, Repair Permissions, etc. All you really need is a comprehensive backup and Recovery solution and use it regularly. And every so often use a tool like Disk Warrior to check for hard drive directory corruption. Thats pretty much it.

With Unix, defragmenting is a bit of a myth. Apple has a doc on this in Apple Support somewhere. So is Repair Permissions for that matter, except in cases of poorly written third party apps. Cache clearing is also a bit of a myth. Doesn't do diddly usually, plus it hampers real troubleshooting.

Thing about drives is they will fail with no warning. They just die for whatever reason. Nothing you did or could of done. They just die. Thus the most important thing you can do is have a comprehensive backup and Recovery solution and use it regularly.

Michael Horton
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Repairing permissions is only for the Boot Volume and I am not aware of what MacJanitor does, but RAID 0 being the fastest and most vulnerable of all RAID sets, is controlled by the MacOS disk utilities setup.

RAID 0 should be considered "temporary storage" just because it IS! We all use RAID 0 and hope it doesn't fail but it can and will at some point. Utilizing a SATA controller card that can set the RAID in firmware outside of MacOS, is helpful when it comes to reinstalling MacOS X or updating the OS at times, because the internal drives setup can be destroyed easily.

Other that that, there not much you can do except only store recoverable data on that RAID set.

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RAID 0 should be considered "temporary storage" just because it IS![/qoute]
It's just like slow RAM.

Use another setup like 3+ or 5+ and as Mike said use a backup solution. Data can vanish any time.
Unix defrag only handles "small" files, and as John says permissions doesn't matter on those drives - except your system runs from it.

Andreas

Not trying to be too flippant. RAID 0 to me is like riding a 1000 cc sportbike riding stoopid fast wearing on shorts, a t-shirt and flip flops just praying that you aren't going to wipe out. I ride such a bike and wear leathers. I would suggest that RAID 5 be a minimum form of protection with a backup scheme in your near future. Hardrive and RAID boxes are cheap now when you are using SATA solutions (forget the Xserve RAID for indiviudal use). I would suggest spending some time on the AMUG.org site if you need cheap RAID solutions.

As far as maintenance goes, what they said.

Otherwise:

Unloading P2 media sounds like you're mostly working in DVCProHD? At full res, you're talking something around 52GB an hour for media storage. Not too bad to handle, and you can use FW800.

The cheapo solution is to backup your media to a FW800 drive (like a 1TB G-Tech) and use your raid for editing the current project only (obviously for better speed, better performance). Then just backup your projectfile at the end of the day onto the FW800 plus any grafix, audio files, etc you may have created and you're pretty safe at less expense.

You could also set the autosave vault to a seperate drive from the raid to add some extra insurance. None of this is as automated a process as Raid5 or higher, but it's a simple enough alternative if cost is an issue. Just takes some commitment.

The scary part you mention is having several current projects on the raid with no backup other than tape layoffs. Don't want to come off sounding too heavy-handed, but that's a bomb ticking.

Clay