Hello,

I've 4 Samsung HD753LJ harddrives. They are in a RAID setup in a home PC/Server and are working "fine".
After a power down of the PC/Server last week I noticed that the drives do not power/spin-up at powering up the PC.
After a while the drives spin-up one by one. It look's like the RAID controller is giving a reset or something on the sata-port and then the drives spin-up.
When all 4 drives are up and running everything works normal. A reboot of the PC works fine.
But when the PC is powered down, then at power up again the drives won't spin-up till the RAID controller is looking for the drives.

So I was thinking about a bad powersupply that can't supply the power to 4 drives. I disconnected 3 drives, but then also no spin-up of the drive at power-up.
I tried the disks one by one in an other pc, same problem. No spin-up at power-up.

So what can be wrong with 4 disk at the same time?
It looks like something with the powercircuit of the drives. Some check at powerup that tells the drive the power ain't stable?
After the "reset" by the controller the power is stable and the drive spins-up?

They appear to be configured to Power Up In Standby (PUIS). You could use HDAT2 to disable PUIS, but why would you want to, assuming that you wish to maintain the RAID array? Staggered spin-up reduces the load on the PSU.

BTW, you need to start HDAT2 with the "/w" switch in order to wake up the drives, ie ...

HDAT2 /W

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A backup a day keeps DR away.

I didn't know about the PUIS option. So i was thinking of a hardware error.
If it's an option it's fine to me. I will check the settings to be sure.

Thanks,

It was the PUIS option.

Nice to know the drives are oke.