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aix:mirror_pool

PowerHA: Cross site mirroring (mirror pools)

While Mirror pool is an AIX 6 concept, PowerHA introduce an additional site location.

Mirror pool is only avalaible on scalable VG (you can convert with chvg -G <VG_name>

Important: To use HACMP site (and also mirror pools), you have to patch HACMP at level 6.1 SP6 minimum

  • First create sites, and associate node(s) to it, do it for all nodes:
# smitty hacmp
--> Extended Configuration
--> Extended Topology Configuration
--> Configure HACMP Sites
--> Add a Site
                Add Site 
                                                      
* Site Name            [howald]                                                                                                
* Site Nodes            cltesth     
  • Synchronize the cluster.
  • Associate the shared disks to a site
# smitty hacmp
--> System Management (C-SPOC)
--> Storage
--> Physical Volumes
--> Configure Disk/Site Locations for Cross-Site LVM Mirroring
--> Add Disk/Site Definition for Cross-Site LVM Mirroring
Choose a site, and associate all disks for this location
                Add Disk/Site Definition for Cross-Site LVM Mirroring

* Site Name                 howald
* Disks PVID                00cf4dc38a509995 00cf4dc38a509995 00cf4db3864e3eff 00cf4db3864e3eff
  • Synchronize the cluster.
  • On each logical volume, on active share VG, change the parameter “Allocate each logical partition copy” to superstrict, and add mirror pool copies
# smitty hacmp
--> System Management (C-SPOC)
--> Storage
--> Logical Volumes
--> Change a Logical Volume
Choose an active VG on the node you want to change
               Change a Logical Volume on the Cluster

  Volume Group Name                                   RG2vg
  Resource Group Name                                 cl6avaloqpreRG2
* Logical volume NAME                                 avapre2lv
  
.......
  Allocate each logical partition copy                superstrict                         +
    on a SEPARATE physical volume?
.......                                                                                   +
  Mirror Pool for First Copy                          mp_howald                           +
  Mirror Pool for Second Copy                         mp_royal                            +
  Mirror Pool for Third Copy                          None                                +   
  • Create Mirror Pool

Mirror pools can only be associated to disks without open LV, else you have to umount the filesystems, or move it to another disk.

# smitty hacmp
--> System Management (C-SPOC)
--> Storage
--> Physical Volumes
--> Manage Mirror Pools for Volume Groups
--> Add Disks to a Mirror Pool
If not create, you have to choose a name for the mirror pool (one per site)
                       Add Disks to a Mirror Pool     
* Mirror Pool                       [mp_howald]                                          
  VOLUME GROUP name                 RG2vg
  Resource Group Name               cltestRG2app_group
  Node Names                        cltesth,cltestr
* Disks to Add to the Mirror Pool   [00cf4dc38a509995]
  • Synchronize the cluster.
  • Add mirror pool name to each copy into the VG:
# smitty hacmp
--> System Management (C-SPOC)
--> Storage
--> Volume Groups
--> Mirror a Volume Group
                            Mirror a Volume Group

* VOLUME GROUP name                                   RG1vg
  Resource Group Name                                 cltestRG1app_group
  Node List                                           cltesth,cltestr
  Reference node
  PHYSICAL VOLUME names
  
  Mirror sync mode                                    Background
  Number of COPIES of each logical                    2
    partition
  Keep Quorum Checking On?                            no
  Create Exact LV Mapping?                            no
  
  Mirror Pool for First Copy                         [mp_howald]
  Mirror Pool for Second Copy                        [mp_royal]
  Mirror Pool for Third Copy                         []       
  • Synchronize the cluster.
  • Force the mirror pool strictness parameter to Superstrict:
# smitty hacmp
--> System Management (C-SPOC)
--> Storage
--> Volume Groups
--> Set Characteristics of a Volume Group
--> Change/Show characteristics of a Volume Group
                   Change/Show characteristics of a Volume Group

* VOLUME GROUP name                                   RG1vg
  Resource Group Name                                 cltestRG1app_group
  Node Names                                          cltesth,cltestr
* Activate volume group AUTOMATICALLY                 no
    at system restart?
* A QUORUM of disks required to keep the volume       no
   group on-line ?
  Enable Volume Group for Fast Disk Takeover?         yes
  Change to big VG format?                            no
  Change to scalable VG format?                       no
  LTG Size in kbytes                                  256
  Set hotspare characteristics                        n
  Set synchronization characteristics of stale        n
   partitions
  Max PPs per VG in units of 1024                     32
  Max Logical Volumes                                 256
  Mirror Pool Strictnes                               Superstrict               
  • Synchronize the cluster.
  • Optional you can activate the Cross-Site LVM Mirroring Verification:
# smitty hacmp
--> System Management (C-SPOC)
--> Storage
--> Volume Groups
--> Set Characteristics of a Volume Group
--> Enable/Disable a Volume Group for Cross-Site LVM Mirroring Verification
  • Set all LV from VG to have the first copy on first site and second on second site:
lsvg -m RG1vg
Logical Volume    Copy 1            Copy 2            Copy 3            
RG1testlv         mp_howald         mp_royal          None              
loglv01           mp_howald         mp_royal          None              
tsmRG1lv          mp_howald         mp_royal          None              
lv01              mp_howald         mp_royal          None              
testownlv         mp_howald         mp_royal          None              
imperva1lv        mp_howald         mp_royal          None              
aaalv             mp_howald         mp_royal          None   
  • Force the varyon, needed for cross-site mirroring
# smitty hacmp
--> Extended Configuration
--> Extended Resource Configuration
--> HACMP Extended Resource Group Configuration
--> Change/Show Resources and Attributes for a Resource Group
- Select a ressource group
 
                                            Change/Show All Resources and Attributes for a Custom Resource Group
  Resource Group Name                                 cltestRG1app_group
  Inter-site Management Policy                        ignore
  Participating Nodes from Primary Site               cltesth
  Participating Nodes from Secondary Site             cltestr
  
  Startup Policy                                      Online On Home Node Only
  Fallover Policy                                     Fallover To Next Priority Node In The List
  Fallback Policy                                     Never Fallback

  Service IP Labels/Addresses                        [cltestRG1]
  Application Servers                                [cltestRG1app]

  Volume Groups                                      [RG1vg ] 
  Use forced varyon of volume groups, if necessary    false         --> To set to true
  Automatically Import Volume Groups                  false   
aix/mirror_pool.txt · Last modified: 2021/01/01 21:21 (external edit)