Only 2 of 4 NVMe SSDs are detected

    Dear Community,


    I am very new in the world of Open Media Vault (7.4.0-2) and I face a first bigger problem. I have a Topton Mini-PC with a Intel N100 CPU. In this PC there are two m.2 PCIx slots for SSD storages. In one of this slots I have mounted a Crucial 2 TB NVMe SSD als system disk, where I have installed O.M.V. In the second slot there is a PCIe x4 adapter to connect other four NVMe SSDs to the mainboard. I have now installed three additional Lexar 4 TB NMVe SSD on this adapter. These SSDs are displayed in the AMI BIOS but the Linux of O.M.V. only displays the first two mounted (m.2 slot 1, m.2 slot 2) on this adapter. Also, if I just mount one or two NVMe SSDs on m.2 slot 3 or m.2 slot 4 they are not recognized in the operating system. I can also not see them in lspci.


    Could anybody give me a hint, what could be the root-cause? Do I maybe need to install additional software to get the NMVe SSDs on m.2 slot 3 and m.2 slot 4 on the PCIe x4 adapter recognized?


    Thankyou for your useful hints in advance.


    Regards from Germany,

    Mic.

  • chente

    Approved the thread.

    First thing I would check is the linux compatibility of that card if the bios see it right but debian does not. Perhaps there is a driver that you need to install.


    You should also check to see if there are any issues with pcie lanes available on that slot. (ie. does the card need 8, but there are only 4 on that slot)

    Hi BernH ,


    thank you for your feedback. The PCIe x4 "Card" is part of the computer, this means it was alrady installed, when I bought the PC. How do I get information which driver I may need? How do I see how much PCIe lanes are occupied? (But, if there is a too low number of PCIe langes, why can I see all four NVMe SSDs in the AMI BIOS?)

    Regards,
    Mic.

    Quote from Mic2024

    Hi BernH ,


    thank you for your feedback. The PCIe x4 "Card" is part of the computer, this means it was alrady installed, when I bought the PC. How do I get information which driver I may need? How do I see how much PCIe lanes are occupied? (But, if there is a too low number of PCIe langes, why can I see all four NVMe SSDs in the AMI BIOS?)

    Regards,
    Mic.


    Since I have no detailed information available on your device, I can't give specifics, so you may have to look at the specifications on the hardware and/or contact the manufacturer if you can't find the information as there is no way that I am aware of to tell otherwise what the motherboard architecture is doing.


    Basically, the concept is this:


    A CPU offers up a certain number of PCIE lanes for the motherboard, storage and expansion cards to use, but they are dedicated to each device.

    As an example, if the CPU offers 16 PCIE lanes, you could use them all for a CPU operating at full speed, or give 8 to a GPU and 8 to be used for 2 NVMe drives, or not use a GPU, and allow them all to be used for storage or some other pcie card, but once they are committed to a device they can't be used for something else.


    With that in mind, you can look up the info on the CPU to determine the number of pcie lanes it offers, and then look in the manual for the system/motherboard and/or expansion cards for any information regarding pcie lane usage by devices. Sometimes you will find information in there regarding the required pcie lane usage for a device and it's impact on other devices.


    It is not uncommon when looking at this information to see references to storage stating things like: if you use an nvme drive in a certain slot it will disable some other slot or combination of slots. This is because the nvme requires a certain number of pcie lanes, and if there is no a pcie controller chip providing more pcie lanes than the CPU offers, it will take what it needs for from the CPU, thereby reducing what is available to other devices.


    In your case, as an example, based on the intel N100 CPU specs, there are 9 pcie lanes provided by the CPU. Assuming there is no additional pcie controller chip to look after other things, and you have 2 nvme drives in the motherboard, with each drive requiring 4 lanes, you now have 8 used and 1 available (usually motherboard nvme slots are x4 speeds, but once again without motherboard information this is just based on common usages) . If the add-on card requires x4 as you mentioned above, it will need 4 of those 9 pcie lanes, but 8 of them are in use by the on board nvme drives, leaving only one lane available to the card, which may be enough for the card to report things in the BIOS, but not enough for the card to operate properly.


    With all of that in mind, as I said, you need to first look for the information on the hardware to see if you are exceeding the capabilities of the hardware pcie lanes as explained above.


    If you are not, then you will have to determine the linux compatibility and/or driver requirements. Most standard linux compatible devices have drivers built into the kernel, but sometimes additional drivers are required, and once again, this is not something I can answer without information on the hardware chipsets and some googling to find the information, of possibly even having querying the manufacturer if general searching does not reveal the information

    Hello Bernd,


    thank you for your feedback again. Unfortunately, I also don’t have detailed information about my Mini-PC. I expected the is an user’s manual in the box or at minimum any kind of type number, type description er equal on the device but it is not. This may be one disadvantage to buy a PC from a Chinese company (which Topton is). I contacted the support of Topton to get more details but I need to wait for their reply.


    I tried to search the web side of Topton. If I compare pictures, I would say this is the most comparable PC but it is described as a Mini-PC with Intel Core i5/i7/i9 CPU and I have the version with Intel N100 Alder Lake CPU.


    Link: https://www.toptonpc.com/produ…0-2xddr5-fanless-mini-pc/


    All the questions you mentioned I also asked myself. I just wonder, why is it also not working when I install just one NVMe SSD on the board on m.2 slot 3 or slot 4.?


    In the AMI BIOS I can find an option where ich can choose between “m.2” and “PCIe x4” but it seems not to have any influence. The option to connect an SATA drive is already disables in the AMI BIOS because I don’t want to use it.


    In the following figure you find some configurations I already tried.



    I will not be able for further tests in the next week but I will come back later for good ideas from all of you.


    Regards,

    Mic.

    Quote from Mic2024

    All the questions you mentioned I also asked myself. I just wonder, why is it also not working when I install just one NVMe SSD on the board on m.2 slot 3 or slot 4.?

    Your diagram does help to understand the situation a bit, as it is difficult to picture the situation based on the written information above. Unfortunately, it doesn't help provide an answer. The fact that you seem to be able to get 2 slots on the card to work, but not the other 2, makes me think you either have pcie lane starvation as I explained above or a defective card. If it was a driver issue I wouldn't expect the card to operate at all, but it is still worth looking into as there may be something unique to that card that requires a "special" driver version.


    I think you really need that specification information/motherboard and card manual to try to understand what is happening.

    Hi Bernd,


    my first worry also was that the x4 adapter or the adapter card is defective. Then I found a complete list of all my installed NVMe SSDs in the AMI BIOS overview. That made me suspicious. Can the adapter really be defective if the AMI BIOS shows me all NVMe SSDs?


    For getting more details and specifications I still need to wait until I get a helpful reply from the Topton support.


    I think it may also worth a try to install an other Linux distribution or a Windows on the PC. I hope to see if any other operating system would recognize the complete set of NVMe SSDs.



    Because the diagram already helped, I upload two photographs here. Maybe it helps, too.


    Thank you and regards,

    Michael.

    Posting to subscribe the thread.

    FYI the board isn't Topton but is a CWWK.


    On holidays but will reply better when return home

    Those pictures do help understand the connections for sure. As I see it, it looks like the card is only using the m.2 adaptor/header card you have noted as slot A on the left.


    This once again makes me think that it may be a situation where populating the m.2 slot in the middle of the board may be disabling 2 of the slots on the card from operating correctly. By this I mean that the system may be a "one or the other" kind of configuration. Either 2 nvme's on the mother board or 4 on the card, but not both. They may still be seen in the BIOS because a chip on the card id reporting it, but not have the required PCIe lanes to operate correctly.


    Trying a different OS (other linux or windows) may help determine if the card is defective, but a quicker/simpler test may be to remove the nvme from the middle slot on the motherboard and place it on the card. That could answer the question of the pcie lane starvation "one or the other" I just mentioned, and determine if the card is functioning. Linux should still boot from it as it doesn't really care what slot a boot drive is in, as long as there is a boot loader and OS on it.


    Once again, without knowing the pcie lane distributions when using the add-on card this is just a guess.

    Additional note


    If you can run dmidecode (piped to either less or more for ease of seeing the output) via ssh or a console, it may list the motherboard info towards the top. This may assist in finding the info online

    With Soma'a help identifying the board as CWWK and looking at the board pictures, does this look like your unit?


    CWWK 12th generation N series 8-core new member Affordable version N305//N200/N100/fanless low power consumption micro mini industrial control host soft routing
    Product Information Product Features 1. Brand new lntel 12th generation N series full small core low power consumption processor 2. 1*SO-DIMM DDR5 memory…
    cwwk.net


    If it is, the rudimentary specs say:


    8. The M.2 x4 interface supports the expansion of 2/3/4 M.2 NVMe x1 adapter boards


    Which makes me think the Lexar NM790 nvme's, being x4 drives, may be able to operate at x2, but not x1, and with the adaptor card being in an x4 slot, the 4 available pcie lanes are given to the first 2 nvme's and the other 2 are starved.

    No, unfortunatelly, this is not my Mini PC. You picture has a much more flat cooler.


    Here a picture from the outside of my PC:

    Quote from BernH

    Trying a different OS (other linux or windows) may help determine if the card is defective, but a quicker/simpler test may be to remove the nvme from the middle slot on the motherboard and place it on the card. That could answer the question of the pcie lane starvation "one or the other" I just mentioned, and determine if the card is functioning. Linux should still boot from it as it doesn't really care what slot a boot drive is in, as long as there is a boot loader and OS on it.

    I have done this. It was my "setup B" in #5.

    Dear all,

    dear BernH ,


    after over a week of doing nothing I made a new test today and I was a little bit suprised. I can see all devices in lspci but still not in lsblk. what does this mean?


    In the output of lspci you can see the lines:

    Code
    01:00.0 Non-Volatile memory controller: Shenzhen Longsys Electronics Co., Ltd. Lexar NM790 NVME SSD (DRAM-less) (rev 01)
02:00.0 Non-Volatile memory controller: Shenzhen Longsys Electronics Co., Ltd. Lexar NM790 NVME SSD (DRAM-less) (rev 01)
03:00.0 Non-Volatile memory controller: Shenzhen Longsys Electronics Co., Ltd. Lexar NM790 NVME SSD (DRAM-less) (rev 01)
[...]
08:00.0 Non-Volatile memory controller: Micron/Crucial Technology P2 [Nick P2] / P3 / P3 Plus NVMe PCIe SSD (DRAM-less) (rev 01)

    These are all 4 NVMe SSDs I have installed.

    Unfortunately, I just got a question but no feedback and support from Topton until now, So I don't have more details. But with the input of Soma I also will ask CWWK, if the know more.


    Installing Windows has previously failed due to Windows hardware requirements not being met. I will try again...

    Regards,
    Mic.

    Hello,


    I have now managed to create a bootable stick for installing Windows 10 that runs on the mini PC. I only needed to get into the setup to see which drives were there. Unfortunately, the result is no better under Windows.



    When I start it for the first time, a drive with 0.00 MB of storage is recognized in addition to the two recognized NVMe SSDs. But after clicking on Update, it is gone. So it is obviously not the Linux fault after all.


    I also tried again to see what happens if I remove the NMVe SSD directly on the mainboard. That didn't work either.



    I also dismounted the slot adapter to mount the m.2 NVMe SSD in slot A.



    In another test, with a little adaptation, I managed to connect the x4 board to the second m.2 slot on the board. When I do that, only one NMVe SSD is recognized on the x4 board.



    The setting in the AMI BIOS, where I can choose between “m.2” and “CSMx4”, doesn’t seem to have any influence. The result is always the same.


    Now I’m a bit confused. What do you say?


    Thanks and regards,

    Mic.

    Based on all that you have posted, I still think you are possibly dealing with a pcie lane starvation issue, which is a hardware problem related tou your configuration.


    Unfortunately, I don't have any other suggestions.

    Hello everyone,


    It's hard to believe, but sometimes the simplest solution is the right one. Last night I had the thought that the previous owner of the mini PC had set it up for maximum energy savings. I thought that he might have changed BIOS settings for this (even though he told me he didn't). So I've now reset all settings in the AMI BIOS to default.


    Immediately afterwards, all NVMe SSDs were correctly recognized. The Windows 10 setup program recognizes them. Debian Linux recognizes them, and Open Media Vault also shows them all correctly in the overview. Wow!



    What can we learn from this? Don't trust anyone if they tell you they haven't changed anything. 🤣


    The disadvantage now is that I unfortunately can't say which BIOS setting was responsible for the problems.


    Thank you very much for your support and the good tips on this matter.


    Regards,

    Mic.

  • Mic2024

    Added the Label resolved

Participate now!

Don’t have an account yet? Register yourself now and be a part of our community!

Register Yourself Login