Le 29/03/2019 à 09:56, Artur Paszkiewicz a écrit : > Unfortunately, there is no simple answer or easy fix for this. Intel RST > is not supported (officially) on Linux, only RSTe/VROC is, but since the > RAID metadata format is generally the same, RST RAID usually just works > with mdadm. > > The problem here is that enabling RAID mode in the BIOS causes that the > drives are not visible. When in RAID mode, the PCH PCIe ports for NVMe > drives are hidden and NVMe registers are remapped under the AHCI BAR. > The standard Linux nvme and ahci drivers can't handle that. There had > been some patches proposed to make this work but they did not get > accepted. You can try to apply them and rebuild your kernel: > > https://marc.info/?l=linux-ide&m=147709610621480&w=2 Thanks a lot for your answer, which clarifies the matter very well. Indeed, while I was searching the web for help, I stumbled on screenshots of BIOS from other MB manufacturers and they did mention "NVMe remapping" (in my MB it seems to be named "RST controlled", there's a setting like this for both M.2 ports). I read the whole thread carefully and, being no developer, I only vaguely understand why the patch was rejected (it's trying make the kernel aware of a dirty quirk in Intel's hardware, which seems to be unwanted by the developers), but on the other hand, it's a pity that Linux users will never be able to enjoy this feature, since it seems to be present in all current Intel-based motherboards (and since nowadays most motherboards are equipped with M.2 ports, and additionally, the price of NVMe devices is constantly decreasing, setups like this one will probably become more and more common). Unfortunately, if the patch wasn't accepted in 2016, recompiling the kernel every time its package is updated in Debian Buster will be a maintenance nightmare for me. Plus, since the patch won't be maintained, I'll be on my own in case of problem. > Or you can disable RAID mode and export IMSM_NO_PLATFORM=1 for mdadm. > Your array should assemble in Linux. The downside: Windows will not see > the RAID. You will have to enable RAID mode every time before booting to > Windows... Thanks for the tip. I tried that (while I'm still tinkering with this new hardware before installing the OSes for real) and it works indeed. Buster's rescue environment was able to assemble the array and start syncing. To be sure that the data is preserved between enabling and disabling RAID mode, I created a partition on the array, and a small text file in that partition. After re-enabling RAID mode, the motherboard again saw the RAID array correctly (I didn't tried to read it though; I don't know any Windows-based rescue tool, let alone one with Intel RST driver), and after disabling RAID mode again, Linux could again assemble the array, mount the partition, and read the file inside it. So this works correctly. Unfortunately, to be honest, even if I don't boot Windows very often, I think that going into the BIOS and enabling RAID mode every time I want to play a game (and disabling it afterwards) will be quite cumbersome, and that's a burden I'm not sure I'll want to carry in the long-term. I'm not sure yet, I'll have to think about it. But again, thanks for your answer, even if it brought only little hope, it was very instructive :) Regards, -- Raphaël Halimi
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