Preclear - Power Issue??

Hi All

I suspect that this is not an UnRAID issue, but would like to know if anyone else has had this, or similar issues.

I am currently running UnRAID (at home) in an HP ML310e v2 with 4 x 3.5" disks and it has been fine for years. So, I decided now is the time to upgrade as I need more space (Plex!!!).

I bought 6 x 6Tb secondhand WD Purple disks. I have also got another identical ML310e v2 which I have removed the 2 x 5.5" DVDs and replaced with a 3 bay 3.5" disk carrier. So, I can now have 7 x 3.5" disks in total but the motherboard only had 2 SATA connectors and the onboard B120 controller only has connections for 4 disks - which meant I could only have a total of 6 disks installed. So, I installed the 6 x 6Tb disks and fired up UnRAID to preclear the disks. 5 finished fine all OK, but one was massively slower than the other 5 during the first pre-read. It also flagged up several SMART health 'pending sector' errors... so I sent it back to the seller and he shipped another.

While waiting I installed a P420i RAID card and set it to HBA mode (all standard stuff as I am running DL380s with the same setup). This means I can now attach up to 8 x SATA disks - so I could install disks in all 7 caddies. When I first powered the machine up with 7 disks, it kept hanging during POST and then crashing. When I removed some of the disks it booted OK... so I assumed that the standard 350W PSU wasn't powerful enough to cope with 7 disks all spinning up at the same time during boot up. So, I ordered a Corsair HX850 850W Platinum Fully Modular Power Supply Unit. The standard 4 bay disk carrier in the ML310e has a proprietary 10 way connector to supply power to the backplane... so I modified one of the molex power cables to supply power to the HP disk backplane and it all seems to work OK.

When the replacement 6Tb disk arrived, I fitted it in the newly upgraded ML310e and precleared it. Again it showed several pending sector errors, so I sent it back and the seller actually built an UnRAID machine to test the next replacement disk before he sent it (a very helpful seller ). Anyway he confirmed the new one was good and sent it to me.

It arrived today, so I plugged it in and started to preclear it again for my own peace of mind and very quickly it flagged pending sectors and for the first time a complete FAIL warning - also another disk which happened to be installed at the same time flagged up a SMART error then cleared;

So I began thinking that this seemed to be too much of a coincidence to have so many failed disks and the common denominator is the machine I am using to test them. So, tonight I booted UnRAID on a standard desktop PC with just the replacement 6Tb disk in and as I write this it is showing a throughput of 180Mb/s and is 7% through its pre-read with no errors (so far).

So, the first thing I can imagine is that there is a power issue or a problem with the P420i RAID card. I have a spare P420i, which I will swap out next week to see if the disk is showing as clear during a preclear run... but on the PSU there is a switch which enables the 12v supply to be run as a single 12v rail or multiple 12v rail mode. Corsirs explanation is;

Quote

Toggle single +12V rail or multi +12V rail mode. In the “SINGLE” position, the full output capability of the power supply’s +12V rail is available to any and all connectors, while in the “MULTIPLE” position, each individual connector has Over-Current Protection so no more than 40A of current can be delivered on any given cable.

Everything I've read says that single/multiple mode makes no difference now!

Anyway - I wondered whether anyone has come across something like this before, or can offer any thoughts/advice?

Thanks