Oracle 10g Laptop/nodeless RAC Howto

INTRODUCTION

————

Let me start by saying that this whole article is rather unorthodox.

That’s why I thought the analogy of hitchhiking was so apt. Also

if you are a hitchhiker, and you happen to be carrying your laptop,

well you can bring along an Oracle 10g Real Application Cluster

to show all your friends. Now there’s a road warrior!

Seriously though, this step-by-step guide does not describe any

supported solution by Oracle. So what good is it? Well a lot

actually. By taking the uncommon route, you often see the

colorful streets, the surprising highways, and undiscovered

nooks. What a great analogy because this is also true in software!

In 2002 I went to Open World and was very excited by the discovery

of the Open Source initiative headed up by Wim Coekerts. One of

their most exciting projects to me was this Oracle 9i RAC running

on Linux with a special Firewire driver patched to allow multiple

systems to mount the same filesystem. That was a tremendous learning

experience, and I wrote up an article, and presented that at the

New York Oracle User Group. Afterward, someone from the audience

came to me and asked if I would present at their user group out

in Edison New Jersey. Both presentations were exciting, and I

think well received.

Of late I’ve happened upon some articles floating around the internet

discussing a single-node AKA laptop RAC setup. How could that work,

I wondered? Perhaps they install virtualization software such as

VMWare to allow a single machine to look like more than one. This

would certainly work in theory. Once I started digging a bit more I

discovered Amit Poddar’s excellent article over at dizwell.com, and

I was intrigued. No virtualization seemed to be required other than

some virtual ethernet interfaces.

I decided to dig my heels in and give it a try. After struggling with

the illustrious and very universally beloved installer for a few months

I finally managed to get all the pieces in place, and get Oracle Real

Application Clusters running with no clustering hardware!!!

Here, my fine friends, are all the gory details of that adventure, which

I hope you’ll enjoy as much as I did writing them down.

Oracle’s model of clustering involves multiple instances (software processes)

talking to a single database (physical datafiles). We’re doing the same

thing here, but both instances will reside on the same machine. This

helps you travel light, save on transportation and learn concepts,

commands, and the architecture. Remember this is not an HA solution,

as there is little redundancy, and with a single disk, you will surely get

abysmal performance.

Let’s get started, what will we need to do? Here’s a quick outline of the

steps involved:

1. setup ip addresses of the virtual servers

2. setup ssh and rsh with autologin configured

3. setup the raw devices Oracle’s ASM software will use

4. install the clusterware softare, and then Oracle’s 10g software

5. setup the listener and an ASM instance

6. create an instance, start it, and register with srvctl

7. create a second instance & undo tablespace, & register it

1. Setup IP Addresses

———————-

Oracle wants to have a few interfaces available to it. To follow our analogy

of a hitchhiker traveling across America, we’ll name our server route66.

So add that name to your /etc/hosts/ file along with the private and vip

names:

192.168.0.19 route66

192.168.0.75 route66-priv

#192.168.0.76 route66-vip

Notice that we’ve commented out route66-vip. We’ll explain more about

this later, but suffice it to say now that the clusterware installer

is very finicky about this.

In order for these two additional names to be reachable, we need

ethernet devices to associate with those IPs. It’s a fairly straightforward

thing to create with ifconfig as follows:

$ /sbin/ifconfig eth0:1 192.168.0.75 netmask 255.255.255.0 broadcast 192.168.0.255

$ /sbin/ifconfig eth0:2 192.168.0.76 netmask 255.255.255.0 broadcast 192.168.0.255

If your IPs, or network is configured differently, adjust the IP or broadcast

address accordingly.

2. setup ssh and rsh with autologin

————————————

Most modern Linux systems do *NOT* come with rsh installed. That’s for

good reason, because it’s completely insecure, and shouldn’t be used at

all. Why Oracle’s installer requires it is beyond me, but you’ll need

it. You can probably disable it once the clusterware is installed.

Head over to http://rpmfind.net and see if you can find a copy for

your distro. You might also have luck using up2date or yumm if you

already have those configured, as they handle dependencies, and always

download the *right* version. With rpm, install this way:

$ rpm Uvh rsh-server-0.17-34.1.i386.rpm

$ rpm Uvh rsh-0.17-34.1.i386.rpm

Next enable autologin by adding names to your /home/oracle/.rhosts file.

After starting rsh, you should be able to login as follows:

$ rsh route66-priv

Once that works, move on the the sshd part. Most likely ssh is already on

your system, so just start it (as root):

$ /etc/rc.d/init.d/sshd start

Next, as the “oracle” user, generate the keys:

$ ssh-keygen -t dsa

Normally you would copy id_dsa.pub to a remote system, but for us we

just want to login to self. So copy as follows:

$ cd .ssh

$ cp id_dsa.pub authorized_keys

$ chmod 644 authorized_keys

Verify that you can login now:

$ ssh route66-priv

3. setup the raw devices

————————-

Most of the time when you think of files on a Unix system, you’re

thinking of files as represented through a filesystem. A filesystem

provides you a way to interact with the underlying disk hardware

through the use of files. A filesystem provides buffering, to

improve I/O performance automatically. However in the case of a

database like Oracle, it already has a sophisticated mechanism for

buffering which is smart in that it knows everything about it’s

files, and how it wants to read and write to them. So for an

application like Oracle unbuffered I/O is ideal. It bypasses a

whole layer of software, making your overall throughput faster!

You achieve this feat of magic using raw devices. We’re going to

hand them over to Oracle’s Automatic Storage Manager in a minute

but first let’s get to work creating the device files for our

RAC setup.

Create three 2G disks. These will be used as general storage space

for our ASM instance:

$ mkdir /asmdisks

$ dd if=/dev/zero of=/asmdisks/disk1 bs=1024k count=2000

$ dd if=/dev/zero of=/asmdisks/disk2 bs=1024k count=2000

$ dd if=/dev/zero of=/asmdisks/disk3 bs=1024k count=2000

Create two more smaller disks, one for the Oracle Cluster Registry,

and another for the voting disk:

$ dd if=/dev/zero of=/asmdisks/disk4 bs=1024k count=100

$ dd if=/dev/zero of=/asmdisks/disk5 bs=1024k count=20

Now we use a loopback device to make Linux treat these FILES as

raw devices.

$ /sbin/losetup /dev/loop1 /asmdisks/disk1

$ raw /dev/raw/raw1 /dev/loop1

$ chown oracle.dba /dev/raw/raw1

You’ll want to run those same three commands on disk2 through disk5 now.

4. Install the Clusterware & Oracle’s 10g Software

————————————————–

Finally we’re done with the Operating System setup, and we can move on

to Oracle. The first step will be to install the clusterware. I’ll

tell you in advance that this was the most difficult step in the entire

RAC on a laptop saga. Oracle’s installer tries to *HELP* you all along

the way, which really means standing in front of you!

First let’s make a couple of symlinks to our OCR and voting disks:

$ ln -sf /dev/raw/raw4 /home/oracle/product/disk_ocr

$ ln -sf /dev/raw/raw5 /home/oracle/product/disk_vot

As with any Oracle install, you’ll need a user, and group already

created, and you’ll want to set the usual environment variables such

as ORACLE_HOME, ORACLE_SID, etc. Remember that previous to this point

you already have ssh and rsh autologin working. If you’re not sure

go back and test again. That will certainly hold you up here, and

give you all sorts of confusing error messages.

If you’re running on an uncertified version of Linux, you may want

to fire up the clusterware installer as follows:

$ ./runInstaller -ignoreSysPrereqs

If your Linux distro is still giving you trouble, you might try

downloading from centos.org where you can find complete ISOs for

RHEL, various versions. You can also safely ignore memory warnings

during startup. If you’re short on memory, it will certainly slow things

down, but we’re hitchhikers right?

You’ll be asked to specify the cluster configuration details. You’ll

want route66-vip to be commented out, so if you haven’t done that and

get an error to the affect of route66-vip already in use go ahead and

edit your /etc/hosts file.

I also got messages saying “route66-priv not reachable”. Check again

that sshd is running, and possibly disable your firewall rules:

$ /etc/rc.d/init.d/iptables stop

Also verify that eth0:1, and eth0:2 are created. Have you rebooted

since you created them? Be sure they’re still there with:

$ /sbin/ifconfig -a

Specify the network interface. This defaults to PRIVATE, just edit

and specify PUBLIC.

The next two steps ask for the OCR disk and voting disk. Be sure to

specify external redundancy. This is your way of telling Oracle that

you’ll take care of mirroring these important disks yourself, as loss

of either of them will get you in deep doodoo. Of course we’re

hitchhikers so we’re not trying to build a system that is never going

to breakdown, but rather we want to get the feeling of the wind blowing

in our hair. Click through to install and you should be in good shape.

At the completion, the installer will ask you to run the root.sh

script. I found this worked fine up until the vipca (virtual ip

configuration assistant). I then ran this one manually. You’ll need

to uncomment route66-vip from your /etc/hosts file as well. Once

all configuration assistants have completed successfully, return to

the installer and click continue, and it will do various other sanity

checks of your cluster configuration.

Since the clusterware install is rather testy, you’ll probably be doing

it a few times before you get it right. Here’s the cleanup if you

have to run through it again:

$ rm rf /etc/oracle

$ rm rf /home/oracle/oraInventory

$ rm rf $CRS_HOME

# these two commands cleanup the contents of these disks

$ /bin/dd if=/dev/zero of=/asmdisks/disk4 bs=1024k count=100

$ /bin/dd if=/dev/zero of=/asmdisks/disk5 bs=1024k count=20

$ rm /etc/rc.d/init.d/init.crs

$ rm /etc/rc.d/init.d/init.crsd

$ rm /etc/rc.d/init.d/init.cssd

$ rm /etc/rc.d/init.d/init.evmd

$ rm /etc/rc.d/rc3.d/S96init.crs

$ rm /etc/rc.d/rc5.d/S96init.crs

Now reboot the server. This will kill any clusterware processes still running.

If you’ve finished the Oracle Universal Installer at this point, and things

seem to be working, check at the command line with the ps command:

$ ps auxw | grep 10.2.0s

root 3728 0.0 0.3 2172 708 ? S May30 0:00 /bin/su -l oracle -c sh -c ‘ulimit -c unlimited; cd /home/oracle/product/10.2.0s/log/bebel/evmd; exec /home/oracle/product/10.2.0s/bin/evmd ‘

root 3736 0.0 5.0 509608 11240 ? S May30 4:51 /home/oracle/product/10.2.0s/bin/crsd.bin reboot

oracle 4047 0.0 2.8 192136 6284 ? S May30 0:00 /home/oracle/product/10.2.0s/bin/evmd.bin

root 4172 0.0 0.3 2164 708 ? S May30 0:00 /bin/su -l oracle -c /bin/sh -c ‘ulimit -c unlimited; cd /home/oracle/product/10.2.0s/log/bebel/cssd; /home/oracle/product/10.2.0s/bin/ocssd || exit $?’

oracle 4173 0.0 0.4 4180 900 ? S May30 0:00 /bin/sh -c ulimit -c unlimited; cd /home/oracle/product/10.2.0s/log/bebel/cssd; /home/oracle/product/10.2.0s/bin/ocssd || exit $?

oracle 4234 0.0 3.9 180108 8808 ? S May30 0:16 /home/oracle/product/10.2.0s/bin/ocssd.bin

oracle 4476 0.0 2.0 24048 4576 ? S May30 0:00 /home/oracle/product/10.2.0s/bin/evmlogger.bin -o /home/oracle/product/10.2.0s/evm/log/evmlogger.info -l /home/oracle/product/10.2.0s/evm/log/evmlogger.log

oracle 6989 0.0 0.1 2676 404 ? S May30 0:00 /home/oracle/product/10.2.0s/opmn/bin/ons -d

oracle 6990 0.0 1.9 93224 4280 ? S May30 0:00 /home/oracle/product/10.2.0s/opmn/bin/ons -d

oracle 7891 0.0 0.2 3676 660 pts/3 S 23:35 0:00 grep 10.2.0s

Also list the nodes you have available to your clusterware software:

$ olsnodes n

route66 1

The Oracle 10g install itself is very trivial, assuming you’ve installed

Oracle before. Use the -ignoreSysPrereqs flag if necessary to start

up the Oracle Universal Installer, and use the software-only option,

as we’ll be creating our RAC database by hand. Also select Enterprise

Edition and things should proceed smoothly. Oracle will recognize that

you have the clusterware installed, and let you know during the

installation.

5. setup the listener and an ASM instance

——————————————-

The listener.ora file is setup as usual, the only difference is you will

include both route66 and route66-vip.

SID_LIST_LISTENER =

(SID_LIST =

(SID_DESC =

(SID_NAME = PLSExtProc)

(ORACLE_HOME = /home/oracle/product/10.2.0)

(PROGRAM = extproc)

)

)

LISTENER =

(DESCRIPTION_LIST =

(DESCRIPTION =

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))

)

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL=TCP)(HOST=route66)(PORT = 1521)(IP = FIRST))

)

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL=TCP)(HOST=route66-vip)(PORT = 1521)(IP = FIRST))

)

)

)

You may also choose to use the actual IP addresses of these hostnames if

you like. One other difference is that you will use Oracle 10g’s new

srvctl utility to start th listener.

$ srvctl start nodeapps -n route66

Ok, on to the fun stuff. It’s time to configure our ASM instance.

Our instance name will be +ASM1, and we’ll set the ORACLE_SID as usual.

In the init+ASM1.ora file specify:

user_dump_dest=/home/oracle/admin/+ASM1/udump

background_dump_dest=/home/oracle/admin/+ASM1/bdump

core_dump_dest=/home/oracle/admin/+ASM1/cdump

large_pool_size=15m

instance_type=asm

asm_diskstring=’/dev/raw/raw1′, ‘/dev/raw/raw2′,’/dev/raw/raw3’

Then in sqlplus startup the ASM instance:

SQL> startup nomount

Next tell ASM how we want to utilize the space we have by creating disk

groups:

SQL> create diskgroup DBDATA external redundancy disk

‘/dev/raw/raw1’,’/dev/raw/raw2;

SQL> create diskgroup DBRECO external redundancy disk ‘/dev/raw/raw3’;

Now that you have diskgroups, you want to make a note of it in your

init.ora:

SQL> !echo “asm_diskgroups=’DBDATA’,’DBRECO'” >> init+ASM1.ora

Now startup your ASM instance:

SQL> startup force

Exit sqlplus and let srvctl know about the new ASM instance:

$ srvctl add asm -n route66 -i +ASM1 -o /home/oracle/product/10.2.0.1

Now you can shutdown in sqlplus, and startup with srvctl:

SQL> shutdown immediate

$ srvctl start asm -n route66

And lastly use the ps command to check for your new instance.

6. create an instance, start it, and register with srvctl

———————————————————

We’re getting to our clustered database slowly but surely. We’re

just getting over the mountains now, and the open road is ahead of

us.

We’re going to create the first of our two instances and call it

BEATNIK. Edit your initBEATNIK.ora as follows:

db_block_size=8192

db_multiblock_read_count=8

db_name=kerouac

BEATNIK.background_dump_dest=/home/oracle/admin/BEATNIK/bdump

BEATNIK.user_dump_dest=/home/oracle/admin/BEATNIK/udump

BEATNIK.core_dump_dest=/home/oracle/admin/BEATNIK/cdump

BEATNIK.instance_number=1

BEATNIK.instance_name=BEATNIK

BEATNIK.thread=1

BEATNIK.undo_tablespace=beatnikundo

HIPPY.background_dump_dest=/home/oracle/admin/BEATNIK/bdump

HIPPY.user_dump_dest=/home/oracle/admin/BEATNIK/udump

HIPPY.core_dump_dest=/home/oracle/admin/BEATNIK/cdump

HIPPY.instance_number=2

HIPPY.instance_name=HIPPY

HIPPY.thread=2

HIPPY.undo_tablespace=hippyundo

You’ll also have to create the /home/oracle/admin/BEATNIK/* and

/home/oracle/admin/HIPPY/* directories.

Now edit the file crKEROUAC.sql as follows:

CREATE DATABASE KEROUAC”

DATAFILE SIZE 250M EXTENT MANAGEMENT LOCAL

SYSAUX DATAFILE SIZE 125M

DEFAULT TEMPORARY TABLESPACE TEMP TEMPFILE SIZE 20M

UNDO TABLESPACE “beatnikundo” DATAFILE SIZE 200M

CHARACTER SET WE8ISO8859P1

LOGFILE GROUP 1 SIZE 10240K,

GROUP 2 size 10240k,

GROUP 3 size 10240k;

There are other parameters you can specify in this create statement, such as

maxinstances, maxlogmembers, and the sys password. However I’ve tried to

simplify it, to make it easier to review and understand. Check the Oracle

docs for details.

Now startup sqlplus and issue:

SQL> startup nomount pfile=/home/oracle/admin/BEATNIK/pfile/initBEATNIK.ora

SQL> @crKEROUAC.sql

Now get the names of your controlfiles from v$parameter and add them to

the initBEATNIK.ora file.

Now add a couple more parameters to your initBEATNIK.ora file:

*.cluster_database=true

*.cluster_database_instances=5

Use sqlplus to stop and start the db again:

SQL> shutdown immediate

SQL> startup force

Now register our new database:

$ srvctl add database d KEROUAC -o /home/oracle/product/10.2.0.1/

$ srvctl add instance -d KEROUAC -i BEATNIK -n route66

Now one more time, shutdown with sqlplus, and then use srvctl to

start the db. From now on srvctl can stop + start the db.

$ srvctl start instance -d KEROUAC -i BEATNIK

7. create a second instance & undo tablespace, & register it

———————————————————–

Since the database is already created, you don’t have to do that step

again. At this point all you have to do is create another instance.

First fire up sqlplus and create another undo tablespace:

SQL> create undo tablespace hippyundo datafile ‘+DBDATA’ size 100m;

Make a copy of your init.ora for the hippy instance like this:

$ cp initBEATNIK.ora initHIPPY.ora

Then set your ORACLE_SID and use sqlplus to startup:

SQL> startup

Finally register with srvctl:

$ srvctl add instance -i HIPPY -d KEROUAC -n route66

8. create data dictionary

————————–

SQL>@?/rdbms/admin/catalog.sql

SQL>@?/rdbms/admin/catclust.sql

10. Some Things to Understand

————————–

Automatic Storage Management

Global Cache Services

Global Enqueue Services

Clusterware procs crsd, evmd, ocssd,oprocd

RAC processes lms, lmd, lmon, lck0

GV$ data dictionary

11. Further Reading

—————–

Clusterware & RAC Install & Configuration Guide for Linux

Clusterware & RAC Administration Deployment Guide

Oracle Technology Network – http://otn.oracle.com

Please visit http://www.iheavy.com or email me at

Thanks to Amit Poddar & dizwell.com

Apress, Oracle Press books