Unable to Recognize the VG Capacity Under the AIX After the LUN Extension

Publication Date:  2012-07-22 Views:  304 Downloads:  0
Issue Description

A LUN on the S2600 is mapped to the AIX host. Later on, the host creates the VG, LV, and FS using the mapped LUN and then mounts them. When the LUN extension is performed at this time, only the extended LUN capacity, not the VG capacity can be recognized on the AIX.

Before the LUN extension

getconf DISK_SIZE /dev/hwdisk0
20452

# lsvg vgdata

VOLUME GROUP:       vgdata                   VG IDENTIFIER:  000507820000d70000000121d30fc7e1

VG STATE:           active                   PP SIZE:        32 megabyte(s)

VG PERMISSION:      read/write               TOTAL PPs:      639 (20448 megabytes)

MAX LVs:            256                      FREE PPs:       538 (17216 megabytes)

LVs:                2                        USED PPs:       101 (3232 megabytes)

OPEN LVs:           0                        QUORUM:         2 (Enabled)

TOTAL PVs:          1                        VG DESCRIPTORS: 2

STALE PVs:          0                        STALE PPs:      0

ACTIVE PVs:         1                        AUTO ON:        no

MAX PPs per VG:     32512

MAX PPs per PV:     1016                     MAX PVs:        32

LTG size (Dynamic): 256 kilobyte(s)          AUTO SYNC:      no

HOT SPARE:          no                       BB POLICY:      relocatable
  

After the LUN extension

# getconf DISK_SIZE /dev/hwdisk0
30480

# lsvg vgdata

VOLUME GROUP:       vgdata                   VG IDENTIFIER:  000507820000d70000000121d30fc7e1

VG STATE:           active                   PP SIZE:        32 megabyte(s)

VG PERMISSION:      read/write               TOTAL PPs:      639 (20448 megabytes)

MAX LVs:            256                      FREE PPs:       538 (17216 megabytes)

LVs:                2                        USED PPs:       101 (3232 megabytes)

OPEN LVs:           0                        QUORUM:         2 (Enabled)

TOTAL PVs:          1                        VG DESCRIPTORS: 2

STALE PVs:          0                        STALE PPs:      0

ACTIVE PVs:         1                        AUTO ON:        no

MAX PPs per VG:     32512

MAX PPs per PV:     1016                     MAX PVs:        32

LTG size (Dynamic): 256 kilobyte(s)          AUTO SYNC:      no

HOT SPARE:          no                       BB POLICY:      relocatable

It can be found that only the extended capacity, not the VG capacity, can be detected by the host.

Product and version information:
  • S2600
  • The OS of the host is AIX
Alarm Information
None
Handling Process
  1. Run the following command to enable the host to recognize the VG capacity online after the LUN extension.

     

    # chvg -g vgdata

     

  2. Check the information about the VG.

     

    # lsvg vgdata
    VOLUME GROUP:       vgdata                   VG IDENTIFIER:  000507820000d70000000121d30fc7e1
    
    VG STATE:           active                   PP SIZE:        32 megabyte(s)
    
    VG PERMISSION:      read/write               TOTAL PPs:      952 (30464 megabytes)
    
    MAX LVs:            256                      FREE PPs:       851 (27232 megabytes)
    
    LVs:                2                        USED PPs:       101 (3232 megabytes)
    
    OPEN LVs:           0                        QUORUM:         2 (Enabled)
    
    TOTAL PVs:          1                        VG DESCRIPTORS: 2
    
    STALE PVs:          0                        STALE PPs:      0
    
    ACTIVE PVs:         1                        AUTO ON:        no
    
    MAX PPs per VG:     32512
    
    MAX PPs per PV:     1016                     MAX PVs:        32
    
    LTG size (Dynamic): 256 kilobyte(s)          AUTO SYNC:      no
    
    HOT SPARE:          no                       BB POLICY:      relocatable
    
    

    The displayed information above indicates the VG capacity is now 952 (30464 megabytes).

     

Root Cause

Without using the command chvg, the host cannot recognize the VG capacity after the LUN extension.

Suggestions
None

END