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  • 1.  NVMe namespaces

    Posted Wed April 05, 2023 08:59 AM
    Edited by Sylvain Wed April 05, 2023 09:08 AM

    Hello,

    I discovered NVMe namespaces and tried to play with them. 

    Show current storage conf :
    [root@p9-2-vio2:/home/padmin]# nvmemgr -S -l nvme1
    ----------------------------------------------------------------
    Name             Location             State            Size
    ----------------------------------------------------------------
    nvme1            01-00                Available        800.17GB
      hdisk1         01-00                Available        800.17GB


    Remove existing namespace : 
    [root@p9-2-vio2:/home/padmin]# nvmemgr -R -l nvme1 -d hdisk1
    Namespace deleted successfully.

    Create new name space :
    [root@p9-2-vio2:/home/padmin]# nvmemgr -C -l nvme1 -s 50GB -b 1
    Namespace created successfully. NSID = 0x1
    Namespace attached successfully.


    Show storage conf :
    [root@p9-2-vio2:/home/padmin]# nvmemgr -S -l nvme1
    ----------------------------------------------------------------
    Name             Location             State            Size
    ----------------------------------------------------------------
    nvme1            01-00                Available        800.17GB
      hdisk1         01-00                Available        50.00GB
      
      
    Then I tried to create a second name space but it fails :
    [root@p9-2-vio2:/home/padmin]# nvmemgr -C -l nvme1 -s 50GB -b 1
    Namespace Identifier Unavailable


    What is the problem ?


    (running on 9009-42G with firmware FW950.60 aka VL950_111 and VIOS level 3.1.2.30)



    ------------------------------
    Sylvain
    ------------------------------



  • 2.  RE: NVMe namespaces

    IBM Champion
    Posted Thu April 06, 2023 02:04 AM

    Multiple namespaces are supported on enterprise type of NVMe disks only - they are configured mainly in systems dedicated to IBM i. Majority of AIX machines are deliver with cheaper NVMe disks without multiple namespaces option...



    ------------------------------
    Igor Novotny
    Principal Consultant
    MHM Computer, a.s.
    Prague 15
    00420602369375
    ------------------------------



  • 3.  RE: NVMe namespaces

    Posted Thu April 06, 2023 04:04 AM

    Hi,
    well IBM offers two different types of NVMe disks for POWER Servers. 
    You are using the low end NVMe Drive, probably Feature Code EC7T:
    800GB Mainstream NVMe U.2 SSD 4k for AIX/Linux

    The offering Information is not updated yet about the Namespace capabilities for those Mainstream drives.

    Only the Enterprise Drives allow more than 1 Namespace:
    See the Offering Information:
    https://www.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_sm/4/897/ENUS9105-_h04/index.html


    Example:

    (#EC5V) - Enterprise 6.4 TB SSD PCIe4 NVMe U.2 module for AIX/Linux
    ...
    This PCIe NVMe device can have 64 namespaces per device.


    AIX commandline nvmemgr command to check the possible Namespaces available:

    # nvmemgr -A -l nvme1 | grep "Number of Namespaces"
    Number of Namespaces (nn) = 0x1

    # nvmemgr -Al nvme1 | grep "single controller"
    NVM subsystem contains only a single PCI Express port.

    I hope that helps.
    Greetings
    Marc-Eric



    ------------------------------
    Marc-Eric Kahle
    ------------------------------



  • 4.  RE: NVMe namespaces

    Posted Thu April 06, 2023 04:56 AM
    Edited by Sylvain Thu April 06, 2023 04:58 AM

    Hi Marc-Eric,

    Thanks a lot for your clarifications.

    I am using EC7Q.




  • 5.  RE: NVMe namespaces

    Posted Thu April 06, 2023 05:05 AM

    Hi,
    you are very welcome.
    ok the EC7Q is also Mainstream and not a Enterprise NMVe:

    (#EC7Q) 800GB Mainstream NVMe U.2 SSD 4k for AIX/Linux

    So only one Namespace would be allowed (check it with the 
    # nvmemgr -A -l nvme1 | grep "Number of Namespaces"

    Greetings
    Marc-Eric



    ------------------------------
    Marc-Eric Kahle
    ------------------------------



  • 6.  RE: NVMe namespaces

    Posted Thu April 06, 2023 05:27 AM
    Yes you’re right !

    # nvmemgr -A -l nvme1 | grep "Number of Namespaces"
    Number of Namespaces (nn) = 0x1