OS X and risks of software raid 0/1

Essence_of_War

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Feb 21, 2013
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Assuming that I make good, regular back-ups w/ time machine and bi-weekly drive images that I keep separate from my time machine back-ups, how risky is a software raid-0 w/ a mac pro?

Specifically, will I lose the array and have to rebuild from back-ups if there is a brownout/power surge/power loss?

Edit:
I should add that I do not presently have a UPS.
If this is a really stupid thing to do without a UPS, I'd love to hear recommendations on UPS also!
 
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vbuggy

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Some people foam at the mouth about it, I have no issues and I now run practically all my Pro's with a boot-stripe-stripe-TM SSD & TM HDD config, (ICH flooding notwithstanding of course - it seems to be able to happen even with two measly drives, but then even the '12 Pro is a creaking antique after all) with previously even three-stripe configs.

Data loss - Probably. Maybe. If you're unlucky. I've lost data thru HDD failures but never due to 'odd' other issues and as you say, if you have regular backups (and in any case apart from large amounts of scratch storage, most of my actually important stuff is pulled from my cloud nowadays) it won't be an issue.

Any decent UPS should be fine. Theoretically speaking it won't save you if your UPS doesn't send a shutdown signal to the Mac ( so obviously look for a compatible one).
 
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Essence_of_War

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OK, good to hear. So it's probably a smart idea to have a UPS for system like this?

What is ICH Flooding?
 

vbuggy

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When the onboard SATA interface is basically at full capacity well below the capability of the SSD's to deliver data.

UPS, certainly. It's highly unlikely to be honest in my experience but without a UPS it is possible to shut down a system inbetween a stripe write, which leaves you with basically a toasted array. As I mentioned, it's best to get one with Mac-aware automatic powerdown control, as e.g. if you're not at your system and the power goes out, the Mac can still suffer the same sort of outage as a forced power-off once the battery runs down.
 

Essence_of_War

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Oh, so saturating SATA, I follow.

So basically an appropriate UPS will both send the system a "park drives and shutdown" signal, and also provide sufficient power for long enough so that it's able to do so.
 

vbuggy

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Well kind of. The Mac will detect a UPS's USB input. E.g. a Back-UPS Pro. Manufacturers who sell a compatible unit should mention this. You can access UPS settings in the Energy Saver control panel. You can decide what happens when based on the runtime of the unit.
 
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sandifop

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Apr 27, 2013
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I am running my home folder (using symlinks) and video projects off a striped 4 volume array (Thunderbolt bus) and have no issues as long as my internal is my boot partition. I back-up hourly using cron (setup using Carbon Copy Cloner) just in case. This works perfectly so far. (2 weeks without issue)

That said, I have a Samsung SSD (830) also on the TB bus. If I boot from there I lose the array (and my home folder) every day. I don't understand why that doesn't work.

The array doesn't seem to have issues being the home volume but working with the Samsung is flakey, for some reason.