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Because I build a RAID 5 atm, I wanted to ask, what would happen if the server with a raid 5 in it (like 4-5 hdds) would have a power supply damage? Can I just switch the power supply and my data is safe and backup again or will there be a raid damage as well?

Thanks in advance.


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up vote 6 down vote accepted

Assuming a battery backed controller, the data should be flushed out to disk and you would be fine. Power supply failure isn't really any different from shutting of the machine unless there was some massive surge.

That being said, raid isn't backup, you must have backup.

Also, if you can afford it, two power supplies on two different power sources ("A/B" power) is always good. I don't have any actual evidence, but from my experience PS is the second most likely thing to fail after hard drives (excluding maybe fans). Anyone know if that is true? I know I have more HDs than power supplies, but this has been the case for me.

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Probably all things considered, hard drives, then fans, then power supplies (with fans), then memory and network and video cards tie at last. I would think it would depend on environmental factors though. Bad power surges, something causing surges in network cabling, etc. would lead to different general failure rates, but anything with moving parts and generating heat will decrease lifespan (and it depends on your ventilation in the room too). Your mileage may vary though. – Bart Silverstrim May 26 '10 at 17:52
+1 for "RAID isn't backup". RAID doesn't protect you from multiple disk failure (be it the P/S cooking the disks, a fire burning the building down, etc) beyond whatever the RAID level you're using allows in individual disk failures. – Evan Anderson May 26 '10 at 17:52
Have another +1 for "RAID isn't backup". Sadly though we see so many people, both here and elsewhere, thinking that backup IS what RAID is about. :( – John Gardeniers May 26 '10 at 18:54
Ya in additional to what Evan said, since RAID replicates instantly for all practical purposes, it replicates mistakes as well, such as deleting files you didn't mean to. – Kyle Brandt May 26 '10 at 19:02

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