On 2017-08-30 17:54, Paul Groves wrote:
So I have discovered that the problem lies somewhere between my PSU and the LTO4 tape drives. The PSU An Antec 80 Plus gold rated 1000W supply.
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Recap: The drive writes for a few seconds. Goes 'donk' then the orange LEDs light up and the drive reboots. At this point I have to reboot the server (probably because SCSI is not hot-swappable).
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So I temporarily installed a lower power PSU into the server (because all of the hard drives and other tape drives are connected). And repeated the test with the ubuntu live usb. And the drives work fine.
Wow :-O
so the remaining puzzle is: why won't the LTO 4 drives work with my expensive Antec Server PSU but they do work with a £7.50 cheapo unbranded chinese supply? And also why do all my other tape drives work fine with the Antec PSU? Is it a problem with the model (HP 1760 SCSI)? But they work fine on another PSU so the LTO4 drives cannot be at fault can they?
Anyone have a clue how to proceed?
Anton hypothesis is the best bet, I think. Using a scope is a good idea. If that turns out to be true, it may be that the older tapes have better internal power filtering while the new ones rely on the PSU. Or it may be that the socket on the new ones doesn't fit well with the old psu and do better with the cheap psu. -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" at Telcontar)