Expanding a block device image with nvmeof-cli

A block device image can be expanded at any time. Use this information to expand a namespace.

About this task

Important: A block device image can be expanded but not reduced.

Procedure

  1. List all namespaces configured on a subsystem.
    Use the NSID output to specify the subsystem to be resized, in step 2. 
    nvmeof-cli --server-address GATEWAY_IP --server-port SERVER_PORT namespace list --subsystem SUBSYSTEM_NQN
    For example, 
    [root@host01 ~]# nvmeof-cli --server-address 10.172.19.01 --server-port 5500 namespace list --subsystem nqn.2016-06.io.spdk:cnode1.group1 
Namespaces in subsystem nqn.2016-06.io.spdk:cnode1.group1 :
NSID| Bdev                    | RBD   | RBD    | Image    | Block | UUID                | Load            | R/W IOs    | R/W MB     | Read MBs   | Write MBs
    | Name                    | Pool  | Image  | Size     | Size  |                     | Balancing Group | per second | per second | per second | per second    
==============================================================================================================================================================
1   | bdev-32c94dd8-8754-     | pool1 | image1 | 1024 MiB | 512 B | 32c94dd8-8754-442f- | 2               | unlimited  | unlimited  | unlimited  | unlimited  
    | 442f-a12c-123abc456789  |       |        |          |       | a12c-123abc456789   |                 |            |            |            |            
--------------------------------------------------------------------------------------------------------------------------------------------------------------
2   | bdev-45c94ee8-ab56-     | pool1 | image2 | 1024 MiB | 512 B | 45c94ee8-ab56-332f- | 1               | unlimited  | unlimited  | unlimited  | unlimited  
    | 332f-a24c-abc123ae7890  |       |        |          |       | a24c-abc123ae7890   |                 |            |            |            |
  2. Expand the block device image.
    To use the namespace resize command, include the --nsid (namespace ID) parameter indicate the new --size.

    The size is indicated in bytes, by default. To indicate a different size type, specify the unit. The supported size units are: K, KB, M, MB, G, GB, T, TB.

    nvmeof-cli --server-address GATEWAY_IP --server-port SERVER_PORT namespace resize --subsystem SUBSYSTEM_NQN --nsid NSID --size SIZE
    For example, 
    [root@host01 ~]# nvmeof-cli --server-address 10.172.19.01 --server-port 5500 namespace resize --subsystem nqn.2016-06.io.spdk:cnode1.group1  --nsid 2 --size 1536
    In this example, the size of NSID 2 on the nqn.2016-06.io.spdk:cnode1.group1 subsystem is being increased to 1536 bytes.