Thursday, 29 January 2015

Power Issues

I've been having significant issues with my system over recent months with hard drive stability. I've been getting regular red ball disks in UnRaid, specific SATA ports have become apparently unusable, not recognising drives attached, multiple errors arising when the do work.

I had thought it was a failing motherboard but as a last resort before replacing it, I went online to check with gigabyte to see if there was a test I could run.

They suggested bios rests, disk and cable swaps etc. all of which I’d done in any case. The final suggestion as PSU replacement - it could be a failing power supply.

My system has a Corsair RM750 installed which powers a variety of devices including 6 internal drives, 6x fans via a fan controller, misc. On my way home from work, I picked up a cheap and cheerful CX650 and dropped it in.

I was seeing the same issues, but in testing and swapping drives around, I noticed that some SATA ports would work with some drives and not with others.

This led me to think there may be differing power requirements for these drives and if the PSU was on the limit, a particular drive might be tipping it over.

The PSU is modular and I was running power from 3 or the available 4 peripheral power sockets on the unit. I thought I’d try adding the 4th line in and powering some of the drives from that. Et Voila! Everything started working on all ports.

I had obviously misunderstood how the PSU output it’s power and had thought all PSU outputs were the same. Apparently, there’s some kind of split going on and by using all 4 outputs, I’ve better tapped the power availability.

Who knew. MediaServer8 is singing again.


Neil (CHBMB - Unraid Forum) said...

I don't fully understand PSUs, but is this related to what people are on about when they talk about the power being supplied by "a single rail"

Just a thought...

Love your blog, have read it from beginning to end and you were the reason I switched back to Unraid from WHS2011 & Transparent Flexraid! Once I knew it was possible to get a DVB-T VM up and running!

Hope you enjoyed the coffee the other week! And hopefully it was Costa not Starbucks....

Peter Mee said...

Enjoyed the coffee alright - Mocha from Peacock Green. Many thanks and much appreciated!

Never really got into PSUs myself, they always either worked or blew up!!

As time goes by, I'm coming to realise I don't need a server full of disks - as capacities increase, I can pretty much fit everything I need onto a few 4TB drives - all my old 500GB and 1TBs are heading into a Windows-based backup server - must do a post on that soon.

Hopefully, with fewer drives, power requirements will be less as well so my power issues might go away.