MaxDB - Administration

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MaxDB Administration

This section again will be fairly large, I will be discussing the following

Installation

Creating and Configuring a database

Adding volumes

Configuring log volumes and log mode

Database backupsLog backups

Database recovery

Consistency checks

Deleting the database

Installation

SAP MaxDB can be freely downloaded from the SAP website, there are a number of version to cover a wide range of operating systems. First I

will discuss how to install MaxDB on a Unix server. Once downloaded you must extract the software either using winzip or SAPCAR, once

extracted you should have the following files

to start the installation as root run the SDBINST command and follow the below

software components

here you have a number of options

0: Server + Client - select this option to install the entire MaxDB server software

1: Client - installs all software exc ept server utilities, database kernel and APO LiveCache apps

2: Custom - gives you an option on what components you want to install

3: None - don't install anything

Select option 2

Custom installation

here you have a number of options available

0: Runtime for SAP AS - install NetWeaver AS on the server

1: DBAnalyzer - only install the DBAnalyzer it also installs Base, M essages, SAP Utilties and DBAnalyzer

2: JDBC - installs Base, SAP Utilities and JDBC

3: Server - only installs the server components

4: Loader - installs components for loading large data volumes via python

5: ODBC - install components that are required for ODBC communications

6: All - all components are installed

7: None - cancel the installation

Select option 3

The installation will now ask a series of questions regarding below, you can change any of the above to suit you own requirement


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Server Installation

(preparing phase)

group name e au : s a)

owner name ( default: sdb)

independent data path (default: /var/opt/sdb/data)

independent program path (default: /opt/sdb/programs)

The installation will go and do some stuff and come back requesting information regarding the database kernel preparing

dependent path (default: /opt/sdb/7603)

Server Installation

(installation phase)The installation will now be carried out in the background, the database is automatically started

Thats all there is to it, you can also use a commandline option to install MaxDB

Installation in the

background./SDBINST -component_group Server -indep_data /var/opt/sdb/data -indep_prog /opt/sdb/programs -o sdb -g sdba

There is also a GUI version called the installation manager, this is mainly used on Windows installation.

If there were any errors or problems installing the software you can view the installation logs

Installation logs

Unix:

/wrk/M axDB_install--.log

Windows:

\wrk\M axDB_install--.log

Creating and Initializing

Before we can crete a new SAP MaxDB instance we need to know what requirements we need for the following

What size should the database be

How much load do you expect the database to have

Now these type of questions are hard to judge when creating databases, if you really have no ideal then have one eye on how you would increase

the the above if the thresholds were meet, for example you know that the data volumes are going to be spread across different disks then try to

match the size of the filesystems with the volume sizes,also allow for additional disks to be added, with load try to have options that you can increase

memory in your server at a later date.

The size of the database is important as depending on the number of data volumes MaxDB configures the number of I/O threads, this is specified by

the parameter_IOPROCS_PER_DEV. SAP recommends 2 for unix systems and 1 from windows systems. If you have two many threads per I/O

may cause a performance bottleneck on the operating system. To calculate the number of data volumes SAP recommends the formula below

Calculate data volumes

You basically use the square root of the total volume size, now for some examples

50GB = 7.07, so round up to 8 data volumes (50 / 8 = 6.25GB each)

75GB = 8.66, so round up to 9 data volumes (75 / 9 = 8.34GB each)

I generally round the size of each volume for eaxample the 6.25GB i would round upto 7GB.

There are a number of restrictions that you must, be made aware of, keep an eye on the latest versions as I suspect these limits will increase withtime

Maximum number of data volumes 4095

Maximum number of log volumes Unrestricted

Maximum size of data volume 512GB

Maximum size of log volume 32TB

Maximum size of entire instance 64TB

Now lets move on to creating the database, I will be using the Database Manager GUI, although being a Unix chap, I will still use a GUI that is

reliable and I have had no problems with this GUI, for the die hard CLI fans I have also given the commandline options.


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Create a Database Instance

Start the SAP Database Manager

The MaxDB Database Manger GUI when open should look something like below

Select the template type

To create the instance you can either select instance -> create or select the c reate instance button (as seen in above

picture), you will be asked to select one of the templates, have choose custom

Desktop/PC - idea for a laptop development database

Custom - use this to change default values, memory size, number of cpu's, etc

My Template - you can even create your own custom template

Database Instanc e Name

Here we can give the Database Instance a name of our choosing, notice that you c an connect to an external MaxDB

server and create Databases


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Installation Version

If you have multiple versions of MaxDB installed you can select any version you want

Advanced Options

There are a number of advanced options you can configure, I generally use them all

Setup the DBM user

Just put in the password of your choice


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Parameter setup

If you have a specific set of parameters that you wish to use then you have the option to use them here, i am just going

for the defaults

Instance Type

Again I am going with the default, OLTP database. LiveCache by the way is a objected-oriented model that also uses the

memory more

Parameter Adjustment

here I tweeked a number of parameters, memory, CPU's and MaxlogVolumes. You can change these settings at a later dat

but the instance will require a reboot


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Volume Setup

By default a data volume and a log volume will be created adjust these to what you planned above,

NOTE: One word of warning if you have selected to install the tutorial you must increase the size of the log volume

otherwise the installation hangs, increase it to at least 1,024MB

Creation Mode

we need to create a password for the dbadmin account

Advanced settings

Some more advanced settings to adjust, if this is a development database i always like the tutorial data to play around

with


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Final Step - Summary page

Finally we get to the summary page, check everything then select next to create the database instance

Creating Database Page

You will now see the creation of the database instance

Finish page

Finally you get the finish page confirming that the installation was successful.


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Database Manager

Once the installation has finished you should see the below in the database manager

Of course you could just script it up which would like something like below

Automated installation

#Database Creation

create_v5_db

# User creation

create_v5_users

Configuring the Database

Once you got the database up and running it time to enchance it, the first thing to do is to mirror the log volumes

Start the database manager GUI, and select instance -> configuration -> log settings, you get the log configuration setting

menu up

Select log mode, then next, the menu will ask which log file to mirror
http://www.datadisk.co.uk/html_docs/maxdb/create_v5_users.txthttp://www.datadisk.co.uk/html_docs/maxdb/create_v5_db.txt


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Mirror Log Volumes

Double click on the single log file and notice the bottom of the configuration screen, the mirror part should have been

filled in with default values, you can change these if so desired

When you named the mirror file you should see it back in the log settings screen

You will be asked to confirm the creation of the mirror log file

To confirm that the log is mirrored select instance -> configuration -> volumes -> select the log volumes button, you will

notice that the "mirrored location" and "mirrored type" are filled in

If automatic backup log mode has not already been configured now is the time to do this,


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Automatic backup log

First you need to create a log backup file select instance -> backup -> backup medium -> right click in the window and

select new medium, fill in the details as you see fit

Select instance -> backup -> backup wizard, Select the Activite/Deactivite automatic log backup

Select the critrea that you need, normally i active a log backup when the log is full

Select on to start the automatic backup log

Once the database has been running a while you will be required to either add a data volume or a log volume, here are the steps to do this

Select instance -> configuration -> volumes, select the next volume on the list and right click and select new volume


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Adding a Data Volume

Select OK to create the additional data volume

the commandline option is as follows

7.6:

dbmcli> param_addvolume 1 DATA DATA_0002 F 50000

dbmcli> param_getvolsall

7.7:

dbmcli> db_addvolume DATA DATA_0002 F 50000


Adding a Log Volume

Select instance -> configuration -> volumes, click on the log volume button to display the log volumes, select the nextvolume on the list and right click and select new volume

Note that because we have selected mirror log volumes (see above) the mirror will also be created

the commandline option is as follows

7.6:

dbmcli> param_addvolume 1 LOG LOG_0002 F 6400


7.7:

dbmcli> db_addvolume LOG LOG_0002 F 6400 PATITION 1


Deleting a Volume (Data or Log)deleting a volume is very simple, select -> instance -> configuration -> volumes, select the volume that you want to delete

right click and select delete.

Backups

As with any system you need to take regular backups, MaxDB has a number of types of backups

Complete and Incremental backup - standard type of backup that is used in most places

Data and log backups - you generally backup the log volumes more than the database volumes (data - once a week, log - everyday)

Parallel backup - used for very large databases, you can use multiple tape drives in parallel

MaxDB has a very nice backup history which you can access via the database manager GUI


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Backup History

select instance -> backup -> backup history

As you can see the backup history page has a lot of information, the action selection may contain the following

Save Warm - a backup (data or log) was implemented

Restore - a recovery of the database was performed

Histlost - an event necessitates a new complete data backup

I am only going to mention backup stategies in that you should have one, my personal one is to perform a full offline backup once a week and to

backup the log files everyday, but I have small database of about 60GB.

Before we can backup the database we need to create a backup medium (a backup device), these can be either

File - standard backup file

Tape - a tape device

Pipe - a third party external backup tool (backint, TSM or NSR)

create backup meduim

using the database manager gui select instance -> backup -> backup medium, right click in the main window an select new

medium

fill in the details giving a name to the backup and stating the filename, etc


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As you can see I have a number of backup mediums, including a log file meduim

Once you have a backup medium you can backup your database

Database Backup

using the database manager GUI select instance -> backup -> backup wizard

Select the backup medium

Comfirm that you are happy then click on start, the backup will start


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After a period the backup should be completed

you can also use a commandline version

dbmcli> medium_getall

dbmcli> util_connect contro l,control

dbmcli> backup_start Full_Backup RECOVERY DATA

second session monitor the backup

dbmcli> backup_state

Log backups are perform using the same procedure, however you must deactive the automatic backup feature before performing a manual logbackup.

Log backup

First deactive the automatic log backup feature select instance -> backup -> backup wizard

The select the log backup


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Then just follow the steps as in the data backup

you can also use a commandline version

dbmcli> medium_getall

dbmcli> util_connect contro l, control

dbmcli> backup_start "LogBackup" LOG

You can check your backups if you desire

check backups

to check your backups select instance -> check -> backup

here you can select to chec k your last backup, a previous backup or select a backup medium, i have select to chec k th

last backup

MaxDb will now go and check the backups, a tick will be displayed against


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Recovery

Recovery is performed in the admin state, therev are two types of recovery

Recovery

Recovery with Initialization

The difference between them is that with initialization data and log volumes are recreated, without initialization the volumes are left untouched

the instance must be in the admin state, select instance -> recovery

Here you have a number of choices, you can even spec ify a specific time. You then select the backup that you want to

restore

Once the data has been restored you then need to apply the log backups


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recovery with initailization

MaxDB will then display a summary screen indicating a successful restore or not

you can of course use the commandline

dbmcli> db_admin -f

dbmcli> util_connect

dbmcli> backup_history_list

## start the first recovery

dbmcli> recover_start "CompleteBackup" data

## start a initialization recovery

dbmcli> db_active recover "CompleteBackup" data

## import all the incremental backups, one after the other

dbmcli> recover_start "IncrementalBackup" pages

## Import the first log backup

dbmcli> recover_start "LogBackup" log 002

## Import any more log backups

dbmcli> recover_replace "LogBackup" "MaxDB_LOG" 003

dbmcli> db_online

Snapshots

From time to time you may wish to performa very large update, snapshots allows you rcover very quickly if the update was unsuccessful. You can

save one snapshot per instance, thus old snapshots are overwritten.

First the instance must be in the ADMIN state, then select instance -> backup -> create snapshot


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Creating a snapshot

select OK and the snapsjot will be created

you can also use the commandline to c reate a snapshot

dbmcli> db_admin

dbmcli> db_execute create snapahot

dbmcli> db_online

Deleting a snapahot

Again the database must be in an admin state, then select instance -> snapshot, select delete snapshot

you can also use the commandline to delete a snapshot

dbmcli> db_admin

dbmcli> db_execute drop snapshot

dbmcli> db_online

Reverting to a snapshot

Again the database must be in an admin state, then select instance -> snapshot, select revert to snapshot

This may take sometime depending on the number of chanes to the database since the snapshot was taken

you can also use the commandline to revert a snapshot

dbmcli> db_admin

dbmcli> db_execute restore snapshot

dbmcli> db_online


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viewing snapshot

To see when the last snapshot was taken see the main database screen, look in the bottom right hand corner you will se

a snapshot section

Consistency Checks

Internal data structures can become corrupted, a consistency check will allow to check the internal structure of the database. You can perform a

consistency check either in online mode or admin mode.

online mode - system checks which will correct saved schemas, relations and indexes

admin mode - all of the above and also renews the converter

Depending on the size of the database this may take a while to complete, so it is best to run it during quiet periods.

select instance -> chec k -> database struc ture

choose the one you want to run, you can speed things up alittle by not checking the indexes


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consistency check

after a while you should get a summary page

you can also use the commandline, here are some examples to check the consistency

## online checks

dbmcli> db_execute check data

dbmcli> db_execute chec k data except index

## offline checks

dbmcli> db_execute check data with update

## online check but specified tables

dbmcli> db_execute check table schema.table catalog

dbmcli> db_execute check table schema.table with long check

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