Monday, July 23, 2012

Managing System Dump Devices on AIX ( lg_dumplv )

http://www-01.ibm.com/support/docview.wss?uid=isg3T1000169


How to create a dedicated dump device


  1. View an estimate of the dump size, enter:
    sysdumpdev -e
    
    You should see information similar to the following:
    0453-041 Estimated dump size in bytes: 25103360
    
  2. View the PP size, enter:
    lsvg rootvg
    
    You should see information similar to the following:
    VOLUME GROUP:   rootvg          VG IDENTIFIER:  0000003173650c77
    VG STATE:       active          PP SIZE:        4 megabyte(s)
    VG PERMISSION:  read/write      TOTAL PPs:      479 (1916 megabytes)
    MAX LVs:        256         FREE PPs:       258 (1032 megabytes)
    LVs:            11  USED PPs:       221 (884 megabytes)
    OPEN LVs:       10  QUORUM:         2
    TOTAL PVs:      1  VG DESCRIPTORS: 2
    STALE PVs:      0  STALE PPs       0
    ACTIVE PVs:     1  AUTO ON:        yes
    
  3. Determine necessary number of PPs (physical partitions). Divide the estimated size (sysdumpdev -e), by the PP size to estimate the proper number of PPs that the dump logical volume should have.
  4. Determine where you have free PPs, enter:
    lsvg -p rootvg
    
    You should see information similar to the following:
    rootvg:
    PV_NAME           PV STATE    TOTAL PPs   FREE PPs    FREE DISTRIBUTION
    hdisk1             active       479         258       78..02..00..82..96
    hdisk2             active       159          0        00..00..00..00..00
    hdisk3             active        75          8        00..00..00..00..08
    
    NOTE: You should use the hdisk with the highest number of free PPs (in this example hdisk1).
  5. Create a LV, enter:
    mklv -y dumplv -t sysdump rootvg 7 hdisk1 
    
  6. Set LV as the dump device, enter:
    sysdumpdev -Pp /dev/dumplv
    
    You should see information similar to the following:
    primary              /dev/dumplv
    secondary            /dev/sysdumpnull
    copy directory       /var/adm/ras
    forced copy flag     TRUE
    always allow dump    FALSE
    
  7. Change always allow dump to TRUE, enter:
    sysdumpdev -K
    
  8. Verify that the flag has been changed, enter:
    sysdumpdev -l
    
    You should see information similar to the following:
    primary              /dev/dumplv
    secondary            /dev/sysdumpnull
    copy directory       /var/adm/ras
    forced copy flag     TRUE
    always allow dump    TRUE
    

2 comments:

  1. hello....

    How to take the backups of SYSdump and Device?

    ReplyDelete
  2. Hello,
    there is no need to backup this device.
    It just provides space for system dumps.

    ReplyDelete