Increasing virtual SCSI device capacity

As storage demands increase for virtual client logical partitions, you can add physical storage to increase the size of your virtual devices and allocate that storage to your virtual environment.

You can increase the capacity of your virtual Small Computer Serial Interface (SCSI) devices by increasing the size of physical or logical volumes. With Virtual I/O Server Version 1.3 and later, you can do this without disrupting client operations. To increase the size of files and logical volumes based on storage pools, the Virtual I/O Server must be at Version 1.5 or later. To update the Virtual I/O Server, see Updating the Virtual I/O Server.

Tip: If you are using the HMC, Version 7 release 3.4.2 or later, you can use the HMC graphical interface to increase the capacity of a virtual SCSI device on aVirtual I/O Server.

To increase virtual SCSI device capacity, complete the following steps:

Increase the size of the physical volumes, logical volumes, or files:
- Physical volumes: Consult your storage documentation to determine whether your storage subsystem supports expanding the size of a logical unit number (LUN). For Virtual I/O Server Version 2.1.2.0, ensure that the Virtual I/O Server recognizes and adjusts to the new size by running the following command: chvg -chksize vg1, where vg1 is the name of the expanding volume group.
  The Virtual I/O Server examines all the disks in volume group vg1 to determine whether they have grown in size. For those disks that have grown in size, the Virtual I/O Server attempts to add additional physical partitions to the physical volumes. If necessary, the Virtual I/O Server determines the correct 1016 multiplier and conversion to a big volume group.
- Logical volumes based on volume groups:
  1. Run the extendlv command. For example: extendlv lv3 100M. This example increases logical volume lv3 by 100 MB.
  2. If there is no additional space in the logical volume, complete the following tasks:
    1. Increase the size of the volume group by completing one of the following steps:
      - Increase the size of the physical volumes. Consult your storage documentation for instructions.
      - Add physical volumes to a volume group by running the extendvg command. For example: extendvg vg1 hdisk2. This example adds physical volume hdisk2 to volume group vg1.
    2. Allocate the increased volume to partitions by resizing logical volumes. Run the extendlv command to increase the size of a logical volume.
- Logical volumes based on storage pools:
  1. Run the chbdsp command. For example:chbdsp -sp lvPool -bd lv3 -size 100M. This example increases logical volume lv3 by 100 MB.
  2. If there is no additional space in the logical volume, complete the following tasks:
    1. Increase the size of the logical volume storage pool by completing one of the following steps:
      - Increase the size of the physical volumes. Consult your storage documentation for instructions.
      - Add physical volumes to the storage pool by running the chsp command. For example: chsp -add -sp sp1 hdisk2. This example adds physical volume hdisk2 to storage pool sp1.
    2. Allocate the increased volume to partitions by resizing logical volumes. Run the chbdsp command to increase the size of a logical volume.
- Files:
  1. Run the chbdsp command. For example:chbdsp -sp fbPool -bd fb3 -size 100M. This example increases file fb3 by 100 MB.
  2. If there is no additional space in the file, increase the size of the file storage pool by running the chsp command. For example:chsp -add -sp fbPool -size 100M. This example increases file storage pool fbPool by 100MB.
  3. If there is no additional space in the file storage pool, increase the size of the parent storage pool by completing one of the following tasks:
    - Increase the size of the physical volumes. Consult your storage documentation for instructions.
    - Add physical volumes to the parent storage pool by running the chsp command. For example:chsp -add -sp sp1 hdisk2. This example adds physical volume hdisk2 to storage pool sp1.
    - Increase the size of the file storage pool by running the chsp command.
If you are running Virtual I/O Server versions prior to 1.3, then you need to either reconfigure the virtual device (using the cfgdev command) or restart the Virtual I/O Server.
If you are running Virtual I/O Server Version 1.3 or later, then restarting or reconfiguring a logical partition is not required to begin using the additional resources. If the physical storage resources have been set up and properly allocated to the system as a system resource, as soon as the Virtual I/O Server recognizes the changes in storage volume, the increased storage capacity is available to the client logical partitions.
On the client logical partition, ensure that the operating system recognizes and adjusts to the new size. For example, if AIX® is the operating system on the client logical partition, run the following command:
```
chvg -g vg1
```
In this example, AIX examines all the disks in volume group vg1 to see if they have grown in size. For the disks that have grown in size, AIX attempts to add additional physical partitions to physical volumes. If necessary, AIX will determine proper 1016 multiplier and conversion to the big volume group.

Last updated: Thu, October 15, 2020