Difference between revisions of "Training-high-availability"

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(Host-based mirroring)
(mdadm)
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  /etc/init.d/multipathd start
 
  /etc/init.d/multipathd start
 
  multipath -ll
 
  multipath -ll
 +
 +
== fdisk ==
 +
Make a little partition for the quorum (SFEX) and a large partition for the rest.
  
 
== mdadm ==
 
== mdadm ==

Revision as of 15:28, 29 April 2009

Contents

Concepts

Cluster Resource Agents are told by the Cluster Manager "start up" or "shut down".

Host-based mirroring

Host-based mirroring is done with mdadm. Besides, there is

  • log shipping
  • synchronous mirroring

Autoyast

install=http://... autoyast=http://...

Migration

A migration in the sense of SAP is a change of OS or DB, but not an upgrade or update.

URLs

IPs

10.31.19.101 sapna1ci
10.31.19.102 sapna1db

Definitions

  • SID is NA1
  • user na1adm id 2000, group 2000
  • user sdb 2001, group 2001
  • user sqdna1 id 2002
  • ascs gets instance number 00
  • ci gets instance number 02
  • we use IBM Java 1.4.2

Decisions

  • We use a simple stack, that means, if a server goes down, the complete stack switches over to the other node, accepting downtime.

Progress

Start multipath

/etc/init.d/boot.multipath start
/etc/init.d/multipathd start
multipath -ll

fdisk

Make a little partition for the quorum (SFEX) and a large partition for the rest.

mdadm

mdadm.conf:

DEVICE /dev/disk/by-id/scsi-360a98000486e5337524a4f6a4e43542d-part2
ARRAY /dev/md0 level=raid0 num-devices=1 UUID=357d721b:86058e8c:8d746cf9:a620ae3c
mdadm --assemble --config /clusterconf/NA1/mdadm.conf /dev/md0

Start lvm

vgscan 
vgdisplay
lvdisplay
vgchange -a y sapvg

Mount the vgs

mount /dev/sapvg/usrsap /usr/sap
mount /dev/sapvg/sapdb /sapdb
mount /dev/sapvg/sapmnt /sapmnt

Java

Install java

yast -i java-1.4.2-ibm

SAP

Install

ASCS

./sapinst SAPINST_USE_HOSTNAME sapna1as

Choose Netweaver -> Application Server ABAP -> MaxDB -> High Availability -> ASCS

DB

./sapinst SAPINST_USE_HOSTNAME sapna1db

Choose Netweaver -> Application Server ABAP -> MaxDB -> High Availability -> db instance

CI

./sapinst SAPINST_USE_HOSTNAME sapna1ci

Start

startsap sapna1as
startsap sapna1ci

Pitfalls

  • forgot to have luns before installing
  • forgot to use SAPINST_USE_HOSTNAME => had to uninstall ASCS