I am trying to drive out the reason I am having some hard drive "hard resetting link" error problems on a Linux Debian box.
I am trying to eliminate the power supply as a problem in trouble shooting, as my problem is probably either software, power supply, or controller as the errors occur on all my SATA ports even after swapping cables and moving around drives.
My question is can a power supply put out correct voltages (tested with a multimeter on a molex connector inline with the hard drives) and still be bad (assume so)? My voltage on 12V was 12.02-12.00 and 5V was 5.04-5.01 while invoking writing operations in all the drives. Supply voltage to the power supply is 122V.
The power supply is a Antec basiq 350W powering a file/webserver/desktop (utilizing VMs) and during periodic checking I have never seen a problem with voltages via the BIOS in the past.
How would I check if the PS is good without purchasing a new PS? (I have no know-good PS to swap in)
Edit: The ports fail at different times usually, some times 2 at a time, but never 4 at one time (based on logs). If I invoke heavy write operations, I can usually get the error to occur, but not always.
Update:
Using information from answers below, I tried to mess with the balance of the drives and the accessories on the two available 12V rails. A long shot but what the heck.
There are two legs of cables with molex connectors from the PS. Assuming (big assumption here) one leg is one rail, and the other on the second rail, I tried isolating the drives to one leg knowing they are pretty lower power devices, and all the accessories and a video card to another not knowing how much they were using together. This configuration left me errors on only one drive, port 1. Then, I focused on that drive. That particular drive was using a Molex-SATA power adapter, AND it was located at the very end of all the connections; also, the drive had both SATA and molex power input options. I switched from the SATA to the molex power input farther up the connection chain and have yet to be able to reproduce the problem on any ports, even with the CPU under 100% load during write operations.
Granted I have seen it takes many hours to get an error, but I was able to reproduce the error on port 1 fairly consistently via heavy writes w/o any CPU load and now can't. Sooo.. I'm crossing my fingers that the problem is found. Buying a PS is much easier than elusive software/firmware/bug issues! Hard to find a solution when you do not know problem!
Thanks to those who gave some insight!
UPDATE: The configuration has stopped the errors on all ports EXCEPT port 2. Not sure weather the drive is failing or the port because it is intermittent and it seems to work fine; until it is not mounted because of the hard reset link. But I think the PS was adding to the confusion and needs replaced with a higher output supply. Thanks again to those that helped!
UPDATE: Bought a quality 550 Watt +/- power supply and have not had issues since. Still kind of annoyed that 350 watts is not enough. 🙂
Best Answer
It is perfectly possible to measure good voltages and still have a bad powersupply.
You suspected that already...
The thing is that a multi-meter is a relatively slow device that won't pick up on very short power-spikes or dips, but these can easily cause a reset of the harddrives.
(There are some multi-meters that can do this, but they are very high-end expensive ones.)
The motherboard is generally not affected as it has it's own voltage regulators that provide some buffering and filtering, thereby isolating the circuits on the motherboard from the worst.
Without a second power-supply there is really no way to tell, but a cheap power-supply, just for testing, won't cost much. $25-$40 will probably get you one. If the system is stable with that you know for sure it was the power-supply. If it is still unstable you have a spare for future use.
But something else: Are you sure you are not overloading the power-supply or running it very close to it's maximum capacity ? 350W could be a little low for a server that also does VM's.
Especially with USA low input voltages (122 V) some power-supplies have serious issues if any of it's output rails needs to deliver more than 85-90% of it maximum rating. Check the label on the power-supply for the max ratings per voltage and do a little calculation what you are powering from it. Just to be sure.