cluster control file

[khilari]

• In a cluster when a package starts the volume group is activated in exclusive mode (what does exclusive mode mean) then filesystems are checked and mounted,, ip address are assigned…. Then what happens (user defined scripts) what r those??? And then services started?? Can you kindly, explain a little on this. Thanks

[Prashanth Waugh · Accepted solution]

Hi Khilari,

cluster: cluster is nothing but the collection of node which cooperate together to improve the the availabilty of application running on node.
===========================================================
Package: All application services ,filesystem,database are grouped together ,network sevices & adress all these things grouped together for running the application is called package.
===================================================================================
exclusive vg activation: #vgchange -a e
exclusive activation modes means only one node will have write access to that VG.
==============================================================================
package startup sequence
1> activate vg
2>check FS
3>mount FS
4>Assign IP
5>start custom defined script
a)start database
b)start application
=======================================

1)activate vg means the node will be able to see and access that VG. in cluser scenario mostly VGs are activated in exclusive mode
2)File system is check before mounting bcoz it will check the integraty of that FS
3)it will mount the FS for that package
4)when package will going to up that time package ip will be assigned to NIC. package ip is nothing but the virtual ip or floating IP.when user is accessing the application that time its directly accessing application through package ip and not the NIC IP.
5)then after that cntl file will call the custom defined script like
a)start database for that application
b)start application
we r calling the script in package control file to start it

Regards
Prashant

[Sandeep_Chaudhary]

1)VGCHANGE="vgchange -a e" # Default

This means vg is activated exclusive mode on one node at a time (remember that in RAC we activate VG in share mode)

2)# VOLUME GROUPS
# Specify which volume groups are used by this package. Uncomment VG[0]=""
# and fill in the name of your first volume group. You must begin with
# VG[0], and increment the list in sequence.
#
# For example, if this package uses your volume groups vg01 and vg02, enter:
# VG[0]=vg01
# VG[1]=vg02
#
# The volume group activation method is defined above. The filesystems
# associated with these volume groups are specified below.
#
VG[0]="/dev/vg02"

this entry defines which vg is part of package which need to be activated.


3)# FILESYSTEMS
# Filesystems are defined as entries specifying the logical volume, the
# mount point, the mount, umount and fsck options and type of the file system.
# Each filesystem will be fsck'd prior to being mounted. The filesystems
# will be mounted in the order specified during package startup and will
# be unmounted in reverse order during package shutdown. Ensure that
# volume groups referenced by the logical volume definitions below are
# included in volume group definitions above.
# LV[0]=/dev/vg01/lvol1; FS[0]=/pkg01a; FS_MOUNT_OPT[0]="-o rw";
# FS_UMOUNT_OPT[0]=""; FS_FSCK_OPT[0]=""; FS_TYPE[0]="vxfs"
#
# LV[1]=/dev/vg01/lvol2; FS[1]=/pkg01b; FS_MOUNT_OPT[1]="-o rw"
# FS_UMOUNT_OPT[1]=""; FS_FSCK_OPT[1]=""; FS_TYPE[1]="vxfs"
#
LV[0]="/dev/vg02/lvol1"
FS[0]="/oramed10p"
FS_MOUNT_OPT[0]="-o delaylog"
FS_UMOUNT_OPT[0]=""
FS_FSCK_OPT[0]=""
FS_TYPE[0]="vxfs"


this entry defines LVOLS from above VG and order in which they should be checked and mounted(in this example only on LV)

[Sandeep_Chaudhary]

4) #IP Address


# at the address prefixes
# IP/Subnet address pairs for each IP address you want to add to a subnet
# interface card. Must be set in pairs, even for IP addresses on the same
# subnet.
#
IP[0]="10.55.244.217"
SUBNET[0]="10.55.244.0"

in this stage which ip address to assign to package is decided.


5)# START OF CUSTOMER DEFINED FUNCTIONS

# This function is a place holder for customer define functions.
# You should define all actions you want to happen here, before the service is
# started. You can create as many functions as you need.

function customer_defined_run_cmds
{
# ADD customer defined run commands.
: # do nothing instruction, because a function must contain some command.

/oramed10p/oracle/local/startstop/oracle_start.sh

test_return 51
}


this is customer defind run script.

after this there is also halt script which is use at the tim eof halting package

[Sandeep_Chaudhary]

here I have just mentioned importand stages apart from that there are some parameter.

[Stephen Doud]

Since you have access to the web, you might want to consider reviewing the actual Managing Serviceguard manual, which will give you more info than this format permits.
http://docs.hp.com/en/ha.html#Serviceguard

[Deepak Kr]

Hi,

To find all answers to your questions refer to following link:

http://docs.hp.com/en/B3936-90117/ch06.html

Once you will go through you can know even more than these queries. SG is really a great product!!

Just have a look!!