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Question about adding NSD devices on a remote node os GPFS cluster

  • 1.  Question about adding NSD devices on a remote node os GPFS cluster

    Posted Sat July 23, 2022 04:01 PM
    Hi

    I'm working in a POC for GPFS (Spectrum Scale) AIX nodes. Our current design is:

    Two nodes in a main location with SAN Connected disk
    On node in a remote location 

    All of them in the same cluster. 

    I have set the NSD in the main location as 4 SAN connected devices and now i want to make those NSD available to the remote node. I'm trying to understand; this is not a remote file system mounting cause all those nodes are in the same cluster, so i have to create NSD devices in the remote node. My question: those NSD devices in the remote node, are not directly attached so i have to create an input file for the mmcrnsd command, something like this:

    %nsd:
    nsd=REMOTEDSK1 # my name for this NSD
    device=/dev/hdisk4 # device name on node k145n05
    usage=dataOnly
    # List of server nodes for this disk
    servers=kamikaze1,kamikaze2
    failureGroup=2
    pool=RemotePoolA

    [root@ /borrar/gpfs ]mmcrnsd -F NSD.input
    mmcrnsd: Processing disk hdisk4
    mmcrnsd: 6027-1662 Disk device hdisk4 refers to an existing NSD nsd1
    mmcrnsd: 6027-1930 Disk nsd1 belongs to file system FS01.

    Yes hdisk4 belongs to a NSD in the nodes kamikaze1 and kamikaze2

    How to create that NSD device that links all those disks in the remote node ???

    TIA


    ------------------------------
    Cesar Daniel Delgado Ponce
    Systems Specialist
    Mercantil Bank Venezuela
    Caracas
    +584166119255
    ------------------------------


  • 2.  RE: Question about adding NSD devices on a remote node os GPFS cluster

    IBM Champion
    Posted Mon July 25, 2022 09:58 PM
    Hi Cesar,
    I am assuming that your existing nodes and SAN are at one site, and you only have network connectivity to the remote server (ie not SAN)?
    If so, you should find that the remote node already has access to the NSDs and can mount the file system once it joins the cluster.  If you check the GPFS / Spectrum Scale concepts manual, you are building a cluster with NSD Servers (your existing nodes) and NSD Clients (your remote node).

    If your SAN is stretched to the remote site, then you just need to change the Server list for each NSD to include the remote node (mmchnsd).

    The Concepts, planning and installation guide covers these concepts quite well, but feel free to ping me if I have missed the intent of your question - or indeed if you have any further questions.
    Have fun!

    ------------------------------
    ========================
    Antony Steel (Red)
    Belisama Pte Ltd
    antony.steel@belisama.services
    ------------------------------

    Original Message


  • 3.  RE: Question about adding NSD devices on a remote node os GPFS cluster

    Posted Tue July 26, 2022 08:37 AM
    Hi Antony

    Thanks for your answer.

    Yes i do have two nodes in a Site 1 with SAN attached disk and another two node in a remote Site 2. My first setup in the Site 1 was very basic in fact i didn't specify a list of servers so i think the NSD was somehow SAN connected ..... Then i change the NSD config to include the nodes of the Site 1 and then another change to include the nodes os Site 2. Now when starting the GPFS i can see the FS i have configured. 

    Thanks again


     


    César Daniel Delgado Ponce.

    Sistemas Operativos Seguridad Distribuidos (6181)
    +58 212 503 0619
    Twitter:@MercantilBanco
    YouTube: Mercantil Banco





    Original Message


  • 4.  RE: Question about adding NSD devices on a remote node os GPFS cluster

    IBM Champion
    Posted Tue July 26, 2022 08:50 AM
    Hi,
    Yes, the NSD definitions only include the servers attached, as they will "serve" the NSDs. Your other nodes will be clients and access the NSDs over the IP network from the NSD servers.
    Correct, if you don't define the servers in the NSD definitions, then those servers will not serve them, just access for local use.

    Have fun, GPFS is one of IBM's best kept secrets. Let me know if you need anymore tips.

    ------------------------------
    ========================
    Antony Steel (Red)
    Belisama Pte Ltd
    antony.steel@belisama.services
    ------------------------------

    Original Message