In this post I’ll demonstrate how to create a Cluster Aware AIX (CAA) cluster on AIX 7.1. I’ll create a simple two-node CAA cluster. I’ll then check the cluster status and, finally, remove the cluster.

 

Before I start, I make sure that both nodes have entries in /etc/hosts on both systems.

 

node1[/] > grep node /etc/hosts

172.29.134.169  node1

172.29.152.160  node2

 

node2[/] > grep node /etc/hosts

172.29.134.169  node1

172.29.152.160  node2

 

I verify that cluster services are not active on both nodes.

 

node1[/tmp/cg] > lscluster -i

Cluster services are not active.

 

node2[/] >  lscluster -i

Cluster services are not active.

 

I’ll now create a cluster named mycluster. My CAA repository disk is named hdisk1.

 

node1[/] > mkcluster -n mycluster -m node1,node2 -r hdisk1

 

My two node CAA cluster is now operational.

 

node1[/] > lscluster -c

Cluster query for cluster mycluster returns:

Cluster uuid: 2a476f06-be50-11e0-9781-66da93d16b18

Number of nodes in cluster = 2

        Cluster id for node node2 is 1

        Primary IP address for node node2 is 172.29.152.160

        Cluster id for node node1 is 2

        Primary IP address for node node1 is 172.29.134.169

Number of disks in cluster = 0

Multicast address for cluster is 228.29.134.169

 

I can immediately execute commands on both nodes using the clcmd utility.

 

node1[/] > clcmd uptime

 

-------------------------------

NODE node1

-------------------------------

  11:16PM   up   1:16,  1 user,  load average: 1.10, 1.18, 1.36

 

 

-------------------------------

NODE node2

-------------------------------

  11:16PM   up 45 mins,  1 user,  load average: 0.97, 0.75, 0.64

 

Prior to cluster creation, the disks on my system were named as follows:

 

node1[/] > lspv

hdisk1          00f6048892b78f9f                    None

hdisk0          00f6050a2cd79ef8                    rootvg          active

 

After cluster creation, hdisk1 is renamed to caa_private0 and is assigned to the CAA repository volume group named caavg_private.

 

node1[/] > lspv

caa_private0    00f6048892b78f9f                    caavg_private   active

hdisk0          00f6050a2cd79ef8                    rootvg          active

 

node1[/] > lsvg caavg_private

VOLUME GROUP:       caavg_private            VG IDENTIFIER:  00f6048800004c0000000131930c1af3

VG STATE:           active                   PP SIZE:        64 megabyte(s)

VG PERMISSION:      read/write               TOTAL PPs:      799 (51136 megabytes)

MAX LVs:            256                      FREE PPs:       784 (50176 megabytes)

LVs:                6                        USED PPs:       15 (960 megabytes)

OPEN LVs:           2                        QUORUM:         2 (Enabled)

TOTAL PVs:          1                        VG DESCRIPTORS: 2

STALE PVs:          0                        STALE PPs:      0

ACTIVE PVs:         1                        AUTO ON:        yes

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

PV RESTRICTION:     none

 

node1[/] > lsvg -l caavg_private

caavg_private:

LV NAME             TYPE       LPs     PPs     PVs  LV STATE      MOUNT POINT

caalv_private1      boot       1       1       1    closed/syncd  N/A

caalv_private2      boot       1       1       1    closed/syncd  N/A

caalv_private3      boot       4       4       1    open/syncd    N/A

fslv00              jfs2       4       4       1    open/syncd    /clrepos_private1

fslv01              jfs2       4       4       1    closed/syncd  /clrepos_private2

powerha_crlv        boot       1       1       1    closed/syncd  N/A

 

node1[/tmp/cg] > df -g

Filesystem    GB blocks      Free %Used    Iused %Iused Mounted on

/dev/hd4           0.25      0.07   74%    10118    37% /

/dev/hd2           2.50      0.19   93%    45192    48% /usr

/dev/hd9var        0.38      0.02   95%     5995    47% /var

/dev/hd3           0.50      0.38   24%      187     1% /tmp

/dev/hd1           0.12      0.12    1%       11     1% /home

/dev/hd11admin      0.12      0.12    1%        5     1% /admin

/proc                 -         -    -         -     -  /proc

/dev/hd10opt       0.38      0.13   65%     8021    21% /opt

/dev/livedump      0.25      0.25    1%        4     1% /var/adm/ras/livedump

/aha                  -         -    -        37     1% /aha

/dev/fslv00        0.25      0.25    2%       15     1% /clrepos_private1

 

Several services are started during cluster creation. In particular you will notice the following subsystems active (lssrc –a output).

 

cld              caa              7340104      active

solidhac         caa              8912986      active

solid            caa              8519794      active

clconfd          caa              9306188      active

cthags           cthags           9830450      active

ctrmc            rsct             3342554      active

IBM.DRM          rsct_rm          8716462      active

IBM.ServiceRM    rsct_rm          9240724      active

IBM.StorageRM    rsct_rm          8061146      active

IBM.MgmtDomainRM rsct_rm          8454200      active

 

node1[/tmp/cg] > lssrc -g caa

Subsystem         Group            PID          Status

 clcomd           caa              6553810      active

 cld              caa              6619252      active

 solidhac         caa              8650856      active

 solid            caa              8781824      active

 clconfd          caa              10092598     active

 

Now I will remove the cluster.

 

node1[/] > rmcluster -n mycluster

 

rmcluster: Removed cluster shared disks are automatically renamed to names such

        as hdisk10, [hdisk11, ...] on all cluster nodes.  However, this cannot

        take place while a disk is busy or on a node which is down or not

        reachable.  If any disks cannot be renamed now, you must manually

        rename them by removing them from the ODM database and then running

        the cfgmgr command to recreate them with default names.  For example:

        rmdev -l cldisk1 -d

        rmdev -l cldisk2 -d

        cfgmgr

 

CAA cluster services are no longer active.

 

node1[/] > lscluster -c

Cluster services are not active.

 

And caa_private0 is renamed back to hdisk1 and the caavg_private volume group is removed also.

 

node1[/] > lspv

 

hdisk1          00f6048892b78f9f                    None

hdisk0          00f6050a2cd79ef8                    rootvg          active

 

node1[/] > df

Filesystem    512-blocks      Free %Used    Iused %Iused Mounted on

/dev/hd4          524288    139136   74%    10097    37% /

/dev/hd2         5242880    405088   93%    45192    48% /usr

/dev/hd9var       786432     88040   89%     5986    35% /var

/dev/hd3         1048576    806528   24%      186     1% /tmp

/dev/hd1          262144    261352    1%       11     1% /home

/dev/hd11admin     262144    261416    1%        5     1% /admin

/proc                  -         -    -         -     -  /proc

/dev/hd10opt      786432    279912   65%     8021    21% /opt

/dev/livedump     524288    523552    1%        4     1% /var/adm/ras/livedump

/aha                   -         -    -        32     1% /aha

node1[/] >

 

 

 

 

Tags:  caa aix caavg_private gibson cluster creation creating chris aware mkcluster 7.1 lscluster