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Installation Guide Adaptive Server Enterprise for IBM RISC System/6000 AIX

Chapter 2 Installation Requirements

Adaptive Server devices and system databases

Adaptive Server devices and system databases

Devices are files or portions of a disk that are used to store databases and database objects. You can initialize devices, using raw disk partitions (for production systems) or operating system files (for nonproduction uses).

Adaptive Server requires the following devices:

• master device - to store system databases.

• sysprocsdev device - to store system procedures.

The master and sysprocsdev devices are created when you create a new Adaptive Server.

master device

The master device contains the following databases:

• master - controls the operation of Adaptive Server as a whole and stores information about all users, user databases, devices, objects, and system table entries. The master database is contained entirely on the master device and cannot be expanded onto any other device.

• model - provides a template for new user databases. The model database contains required system tables, which are copied into a new user database with the create database command.

• tempdb - the work area for Adaptive Server. Each time Adaptive Server is started, the tempdb database is cleared and rebuilt from the model database.

• The sample databases are stored on the master device at installation, but should be moved to a user-defined device after installation. For more information, see "Sample databases" and "Optional devices and databases".

  For recovery purposes, Sybase recommends that you do not create other system or user databases or user objects on the master device.

sybsystemdb device and database

For new installations the master device also contains the sybsystemdb database. The sybsystemdb device stores the sybsystemdb database, which stores information about transactions in progress, and which is also used during recovery.

The sybsystemdb database is required to support distributed transaction management (DTM) features. Before installation, make sure you have enough space available on the default segment to support sybsystemdb.

See Chapter 8, "Upgrading Sybase Servers " for instructions on how to create the sybsystemdb device and sybsystemdb database.

For recovery purposes, Sybase recommends that you do not create other system or user databases or user objects on the master device.

sysprocsdev device

The sybprocsdev devices stores the sybsystemprocs database, which contains most of the Sybase-supplied system procedures. System procedures are a collection of SQL statements and flow-of-control statements that perform system tasks; for example, sp_configure.

The system procedures that are needed during recovery situations are stored in the master database.

sysprocsdev is the default system name for this device. However, it is frequently referred to as the sybsystemprocs device, since it stores the sybsystemprocs database.

Optional devices and databases

The following devices and databases are needed only if you configure Adaptive Server for optional functionality, like auditing or two-phase commit transactions.

The sybsecurity device stores the sybsecurity database and the auditing system procedures with which you can configure auditing for your system.

The auditing system records system security information in an Adaptive Server audit trail. You can use this audit trail to monitor the use of Adaptive Server or system resources.

Install auditing using the auditinit utility. The sybsecurity device is created as part of the auditing installation process.

See Configuring Adaptive Server Enterprise for instructions on how to configure Adaptive Server for auditing.

The auditing system is discussed in more detail in the System Administration Guide.

The pubs2 and pubs3 databases are sample databases provided as a learning tool for Adaptive Server. The pubs2 sample database is used for most of the examples in the Adaptive Server documentation; other examples use the pubs3 database. Both are available in U.S. English versions of Adaptive Server.

The interpubs database contain French and German data. jpubs contains Japanese data.

For information about installing the sample databases, see "Installing sample databases ".

For information on the contents of these sample databases, see the Transact-SQL User's Guide.

The syntax database, sybsyntax, contains syntax help for Transact-SQL commands, Sybase system procedures, Adaptive Server utilities, and Open Client routines. You can retrieve this information using the system procedure sp_syntax.

For example, to see the syntax of the Transact-SQL select command, enter:

sp_syntax "select"

Adaptive Server includes a script for creating the sybsyntax database.

For instructions on how to install sybsyntax, see "Installing online help for Transact-SQL syntax ".

For more information about sp_syntax, see the Reference Manual.

The database consistency checker (dbcc) provides commands for checking the logical and physical consistency of a database. The dbccdb database stores the results of dbcc when dbcc checkstorage or dbcc check verifying are used.

dbcc checkstorage records configuration information for the target database, operation activity, and the results of the operation in the dbccdb database. Stored in the database are dbcc stored procedures for creating and maintaining dbccdb and for generating reports on the results of dbcc checkstorage operations.

For information on installing dbccdb see Chapter 25 of the System Administration Guide, "Checking Database Consistency."

dsync option on by default for database device files

The dsync option is used with the disk init and disk reinit commands. By default, Adaptive Server enables dsync for database device files. This option ensures that Adaptive Server can recover data from devices on file systems. However, dsync can cause a degradation in performance for device files that experience high write activity.

When you install a new 12.x Adaptive Server, by default dsync is set on for all devices.

When you upgrade a UNIX server that stores databases on UNIX file system devices, by default dsync is set:

• on for the master device

• off for all other devices.

See also, sp_deviceattr, and sp_helpdevice in the Reference Manual.

Determining the location, type, and size of a database device

Adaptive Server requires several database devices. Table 2-13 below shows baseline values for each of the devices. See the release bulletin for any last-minute changes to these values.

For all databases you can use either a raw partition or a file.

Sybase Adaptive Server supports the database devices on NFS- and CIFS-mounted devices with Network Appliance Filers for storing data. Network appliance filers provide the same performance and data integrity as raw devices. There are no changes needed to the operating system or to Sybase Adaptive Server to use network appliance filers.

NFS mounted devices have been tested on Solaris, HP/UX, IBM AIX, Windows NT, Linux, and SGI.

Previous versions of Adaptive Server performed buffered writes to file devices, which does not ensure recoverability. Starting in version 12.0, the default for writes to file systems is unbuffered, so files are now acceptable as database devices.

You may need to repartition the disk you choose. Contact your operating system administrator for assistance.

When preparing a raw partition device, follow these guidelines:

• Do not initialize a database device on the partition that contains your Sybase installation software. Doing so destroys all existing files on that partition.

• A raw partition designated for use by Sybase cannot be mounted for use by the operating system for any other purpose, such as for file systems or swap space.

• After a Sybase configuration utility or the disk init command has initialized a portion of a partition as a database device, the entire partition cannot be used for any other purpose. Any space left on the partition beyond the size specified for the device becomes inaccessible, unless you drop and re-create the device.

• For best performance, place the Sybase software and all disk devices, including the master device, on the same machine.

• Place the database device on a character device, because the Adaptive Server recovery system needs unbuffered system I/O. The character devices are in the /dev directory.

To determine whether a device is a block device or a character device, run this command on the /dev directory:

ls -l

"b" (block) or "c" (character) appears in the left-most column.

1. Determine which raw partitions are available.

2. Determine the sizes of the raw partitions.

3. From the list of available raw partitions, select a raw partition for each device, based on the size recommendations in Table 2-13.

4. Verify that the device is a character device.

5. Verify with the operating System Administrator that the partition you have chosen is available.

6. Make sure the "sybase" user has read and write privileges to the raw partition.

   For more information on choosing a raw partition, see your operating system documentation.