[mythtv-users] Software RAID (was: Where are those new 1TB drives?)

[Matthew McClement]

John Drescher wrote:
>> Very cool. Have you tried RAID 5 with FreeNAS? Does it require a
>> powerful processor? And how DO you power all those drives?
>>
> I do not use FreeNAS. I am running all my raid servers (mostly
> software raid6 using madam) on 64 bit gentoo. And for the machine with
> 17 drives ( dual processor opteron 246 + 4 GB memory ) I have 2 400W
> supplies with all the hard drives on one power supply and everything
> else on the other. I did actually add a dummy load on the power supply
> that is connected to the hard drives because it required a minimum
> load on the 3.3V rail which was not being met. Right now I would just
> get a 600 or 700W supply and use that instead.

I do something similar for my home fileserver(560W power supply for the
14 RAID drives, another 560W for the motherboard and OS drives). The
second supply is overkill, but it was a spare.

The biggest thing to remember is that you need a supply with a strong
single 12V rail for the drives. Most Tagan's allow you to toggle between
split and single rail and PC&P also make large single rail PSU's.

I've always sized my supplies based on the total *max* draw of all the
drives combined. This is not the figure on the drives themselves, you
usually have to dig around the spec sheets for this figure.

Matt