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Configuring additional disk volumes for z/OS virtual server instances

You can add an additional volume to a z/OS virtual server instance and designate it for use in z/OS. For example, adding an SVC dump volume to provide a representation of the virtual storage for the system when an error occurs.

Before you begin

Complete the following prerequisites:

  1. Create a z/OS virtual server instance in the IBM Cloud Virtual Private Cloud (VPC) environment and make sure that the instance is accessible through 3270 connection. For more information, see Creating virtual server instances and Connecting to z/OS virtual server instances.

  2. Make sure that you can edit the z/OS virtual server instance through the IBM Cloud console. For more information, see Managing z/OS virtual server instances.

Adding disk volumes

Complete the following steps to add disk volumes:

  1. Attach a new block storage data volume to your z/OS virtual server instance. For more information, see Attaching a block storage volume External link icon.

    Important:

    • If your z/OS instance is created by using one of the IBM-provided z/OS stock images, the size of the new block storage volume must not exceed 55 GB. The storage volumes larger than 55 GB are considered to be Extended Address Volumes (EAV). To work around this restriction and use larger volumes, you must run the command SETSMS USEEAV(YES) on the z/OS instance before you attach a larger block storage device. If you are using EAV volumes, you must also ensure the intended use case for the additional volume supports EAV.
    • In addition to running the command SETSMS USEEAV(YES), you also need to harden this new system setting in system parmlib in case the z/OS system is shut down and re-IPLed. Otherwise, the setting might be reverted to the default USEEAV(NO).
  2. Verify that the newly attached storage volume is attached to and ready to be used by the z/OS virtual server instance.

    A message is sent to the broadcast data set with the affected device address. See the following message as an example.

    IKJ56455I IBMUSER LOGON IN PROGRESS AT 15:19:05 ON JUL
    Preparing attached block storage vde of size 55G    
    Attached block storage vde on address DD60           
    READY
    

    You can also issue OPER and SE LIST commands sequentially to display your device address information.

  3. Initialize the volume through an ICKDSF job and vary it online.

    1. If your z/OS instance is not created by using one of the IBM-provided z/OS stock images, use ISPF (3.2) and create a new data set (for example, IBMUSER.JCL) to store the INITVOL JCL. For example, the data set can be created with the following settings:

      Space units . . . . . . TRKS
      Primary quantity. . . . 10
      Secondary quantity. . . 1
      Directory blocks. . . . 5
      Record format . . . . . FB
      Record length . . . . . 80
      Block size  . . . . . . 3120
      

      If your z/OS instance is created by using one of the IBM-provided z/OS stock images, skip this step, and use the existing IBMUSER.JCL data set for the JCL member to be created in the next step.

    2. Using ISPF (2 or 3.4), create a new data set member (INITVOL) with the following JCL that references the address of the new disk (for example, DD60).

      • You can use the following settings for a non-SMS (Storage Management Subsystem) managed volume:

        //INITVOL  JOB CLASS=A,MSGCLASS=H,MSGLEVEL=(1,1),NOTIFY=&SYSUID.,
        //         REGION=0M                                                  
        //STEP1    EXEC PGM=ICKDSF                         
        //SYSPRINT DD SYSOUT=*                                      
        //SYSIN    DD *                                             
            INIT UNITADDRESS(DD60) VOLID(SDUMP1) VERIFY(*NONE*) +
            VTOC(0,1,225) NODSEXIST
        /*
        

        In this example, a VOLID of SDUMP1 is used because VOLID(SDUMP1) is one of the three volume IDs (SDUMP1, SDUMP2, and SDUMP3) that are preconfigured in the SDUMP settings on the standard z/OS stock image.

        If you are using the z/OS dev and test stock image, then initializing a volume specifically for SDUMP is not recommended, and you need to initialize an SMS-managed volume instead.

        The size of the VTOC depends on the number of data sets that you intend to place on the volume. A larger VTOC size might be needed if you want to allocate extended address volumes (EAVs). You can adjust the size of the VTOC depending on your use case.

      • To initialize an SMS-managed volume, you can use the following settings:

        //INITVOL  JOB CLASS=A,MSGCLASS=H,MSGLEVEL=(1,1),NOTIFY=&SYSUID.,
        //         REGION=0M                                                  
        //STEP1    EXEC PGM=ICKDSF                         
        //SYSPRINT DD SYSOUT=*                                      
        //SYSIN    DD *                                             
            INIT UNITADDRESS(DD60) VOLID(USER00) NOVERIFY +
            VTOC(0,1,225) NODSEXIST STGR
        /*
        

        In this example, VOLID(USERxx), xx can be 00 to 0F.

        Several SMS storage groups in the dev and test stock image can be used. USERxx volumes are placed in the default SMS pool that is associated with Storage Class SCBASE and Storage Group SGBASE.

        The size of the VTOC depends on the number of data sets that you intend to place on the volume. A larger VTOC size might be needed if you want to allocate extended address volumes (EAVs). You can adjust the size of the VTOC depending on your use case.

    3. To submit the job that you are editing with the ISPF editor, first save any changes that you made, then enter the SUBMIT command on the command line of the edit panel.

    4. Using ISPF (S or 13.14), open SDSF (Spool Search and Display Facility).

    5. Using SDSF (ST), view the status of jobs. An active job that is called INITVOL must be running and is waiting for confirmation to initialize the volume.

    6. Enter s next to the INITVOL job to view the job output log. Toward the top of the log, there is a prompt waiting for confirmation to initialize the volume.

    7. Using SDSF, reply to the prompt to confirm and initialize the volume. For example,

      /R <num>,U
      

      The INITVOL job must complete and no longer be an active job. Check the job log again to confirm that the job completed successfully.

    8. Using SDSF, vary online the new disk device based on the address. For example,

      /V DD60,ONLINE
      

      If an error message VARY ONLINE - CU AUTHORIZATION FAILED shows, you can safely ignore it, because z/OS virtual server instances are in an emulated environment and there are no control units.

    9. Using SDSF, verify that the device is online and ready.

      /D U,DASD,ONLINE
      
  4. Optional: If your z/OS instance is not created by using one of the IBM-provided z/OS stock images, run the appropriate TSO command in the z/OS instance to add the volume ID of the newly formatted volume to the list of target volumes for SDUMP if this is your intended use case. For example, SDUMP1 is the volume ID of the newly formatted volume.

    DD ADD,VOL=(SDUMP1)
    

    If your z/OS instance is created by using one of the IBM-provided z/OS stock images, you can skip this step because SDUMP is pre-configured to look for volumes with volume IDs: SDUMP1, SDUMP2, or SDUMP3. In addition, the dev and test stock image uses SMS and new system DUMPs are placed on SMS volumes by default. The ADD command does not persist the change. For this change to persist over future system IPLs, make the corresponding changes to the appropriate parmlib (for example, SYS1.PARMLIB(COMMND00)).

  5. Create a z/OS UNIX System Services file system and mount it to a new directory. A new volume is not necessarily required to add a file system for a new directory because any existing space can be used if there is sufficient amount for your requirements.

    The following example assumes the use of an SMS-managed placement for the new file system. Other options of the zfsadm command can also be used to direct the allocation to specific volumes.

    1. You can use the following zfsadm command to run from the OMVS shell and define a new 5 MB zFS file system named OMVS.IBMUSER.TEST.

      IBMUSER :/u/ibmuser : > zfsadm define -aggregate omvs.ibmuser.test -megabytes 5 IOEZ00248I VSAM linear dataset omvs.ibmuser.test successfully created.
      
    2. To format the file system as a zFS compatibility mode aggregate, you can use the following settings:

      IBMUSER : /u/ibmuser : > zfsadm formate -aggregate omvs.ibmuser.test
      IOEZ00077I HFS-compatibility aggregate OMVS.IBMUSER.TEST has been successfully created.
      
    3. To mount the file system to a newly created directory, you can use the following settings:

      IBMUSER : /u/ibmuser : > mkdir /u/ibmuser/newdir
      IBMUSER : /u/ibmuser : > mount -t zfs -f OMVS.IBMUSER.TEST /u/ibmuser/newdir
      
    4. To ensure that this new file system is mounted again after you restart a system, you must also update the appropriate BPXPRMxx system parmlib member.

  6. Optional: If your new volume is a non-SMS managed volume and you want to allocate new data sets directly to it, you need to specify SCNOSMS as the storage class when you allocate data sets through ISPF (3.2).