[OSX-Users] Re: opinion: standalone smaill raid array

[Terry Payne]

On 5 Jan 2010, at 20:03, Philip Boulain wrote:

> Terry Payne wrote:
>> Drobo is a propriety RAID system...
> 
> Dare I ask what the point of RAID in a *home* NAS is? RAID is good to keep availability up for things like the ECS servers, but it's hardly a data reliability mechanism when both drives are the same age from the same manufacturer, likely from the same batch, subjected to the same load patterns, mounted in the same physical case, hooked up to the same power supply, and controlled by the same software.

The point of a RAID at home, and in particular - Drobo?

Simple!  I was fed up of migrating my iTunes archive from a 100Gb -> 220Gb -> 500 Gb, to then have a power-supply failure (not disc), which still scared the hell out of me.

Drobo gave me an incremental way of upgrading my capacity without the hassle of migration, and the *bonus* of getting some degree of safety given a single disc crash.  Is this the best way of getting protection?  Better than relying on a single disc, and when your archive is 1.7Tb (and growing), getting a disc for backup that is on average 2-3 times your working data size is can cost!

More to the point - having to buy potentially two new external discs each time I migrated started to be way too expensive.  Mebbie I'm taking a chance right now in *just* relying on the drobo, but I do have a copy of most of the valuable content on a separate disc.

Down the line I'll pick up a second Drobo to act as a mirror for my collection, but all in good time...

So the issue is - do you want expandable storage with some protection, or fixed storage with mirrored backup?  For the former - Drobo is a good option, the latter, Time Machine with a fat disc!

> Hugh's suggestion of a Time Capsule, or the also popular combination of putting a big external drive on a Mac Mini, seems more practical to me; no proprietary RAID hardware meddling with the disk layout and making it unreadable by anything else.

It *all* depends on what you need!  If you are media rich (and also dynamic), then be careful with traditional backup systems.  I have an eyetv box which I use to record most the content I consume from the TV - this may get edited, and then exported to an iTunes archive.  If you assume a 1hour episode of some series or other is about 2-3Gb, and you record 4-6 hours of this content, then 12-16Gb per week could be recorded.  If you are faithfully backing this stuff up via Time Machine, then that is a lot of data potentially travelling over Wifi, and then filling up you backup archive (despite you watching the episode and deleting).  Best not to back this stuff up... but then what about that series you didn't get around to watching but downloaded the whole series for the winter???

A RAID gives me some protection, but without the hassle of finely tuning backup policies, or having to periodically maintain the backup archives.  Incidentally, I also have a Time Machine archive which backs up the main disc activity, but it leaves the media archive to do its own thing.  Hmmm... different tools for different tasks....!

Look at your requirements and the options - don't just go with one or t'other option because of us evangelists, or cynical nay-sayers!

	Terry

> 

> 
> -- 
> | Philip Boulain   PhD student | The human race will begin solving its |
> | IAM, ECS, Uni of Southampton | problems  on the day  that it  ceases |
> | http://zepler.net/~lionsphil | taking itself so seriously.-Discordia |


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