B
Oracle Real Application Clusters Preinstallation Tasks

This appendix describes the required preinstallation tasks for Oracle9i cluster software on Windows Server 2003. Windows-specific information is described in this section.

This appendix contains these topics:

• Real Application Clusters Installation Requirements

• Real Application Clusters Preinstallation

• Voting Disk Preinstallation

• Shared Disk Configuration

• Using Oracle Cluster Setup Wizard

• Raw Partitions for Datafiles

• Transferring the Contents of a Raw Partition to a Standard File System for Backup

• Deleting Oracle Operating System Dependent Clusterware

• Troubleshooting the Real Application Clusters Installation

  See Also: The Oracle9i Real Application Clusters documentation set included in the 32-bit documentation library: Oracle9i Real Application Clusters Documentation Online Roadmap Oracle9i Real Application Clusters Concepts Oracle9i Real Application Clusters Setup and Configuration Oracle9i Real Application Clusters Administration Oracle9i Real Application Clusters Deployment and Performance

Real Application Clusters Installation Requirements

In addition to the system requirements listed in Chapter 2, "Preinstallation Requirements", you must meet these requirements:

Hardware

Each node in a cluster requires the following hardware:

• External shared hard disks

• Certified hardware configurations

Hardware and Network Configurations

Have the following hardware and network configuration information available:

• The public network names (known as host or TCP/IP names) of each node

• Whether you have a high-speed private interconnect and, if so, what are the private network names of each node

• Whether you are using Virtual Interface Architecture (VIA) hardware and, if so, what are the available Network Interface Card (NIC) names

Software

Each node in a cluster requires one of the following software types:

• Oracle Corporation certified vendor-supplied operating system dependent clusterware layer

• Oracle operating system dependent clusterware layer

RAM

512 MB for each instance

Real Applications Clusters Installation Considerations

Oracle Corporation recommends that you:

• Install Real Applications Clusters on a Windows workgroup or a Windows domain. For a domain, each node must be a member of the same domain or belong to a trusted domain.

• Do not store the Oracle home and the Oracle database files on the same partition or logical drive for optimal Oracle Cluster File System (OCFS) performance.

• Set appropriate allocation unit sizes. For volumes that store Oracle datafiles, the allocation unit size should be set to 1024 KB or greater.For volumes on which the Oracle home is created, the allocation unit size should be set to 4 KB to 8 KB.Use the Windows disk administration tool to set the file allocation unit size appropriate for the type of file access. The default for Windows file allocation unit size is 4 KB.

  Table B-1 Recommended Allocation Unit Sizes

  File Type	Recommended Allocation Unit Size
  Cluster File System for Oracle Home Only	4 KB to 8KB
  Cluster File System for Oracle datafiles	1024 KB minimum

• Guard against unnecessary troubleshooting, downtime, and performance problems. Do not create Real Applications Clusters partitions on a domain controller or on a DHCP, WINS, or DNS server.

• Oracle Corporation strongly recommends that third party products that require a file system to aggressively cache not be used with OCFS to avoid conflicts with the caching mechanism used by OCFS. OCFS does not cache data for Oracle database files. Instead it performs caching for both metadata and non-database files.

Network Considerations

Do not use a public interconnect for your cluster database. Public interconnects experience busy network traffic. Do not use DHCP to dynamically assign IP addresses to the nodes on which you run cluster databases. DHCP produces increased network traffic through leasing and revoking IP addresses.

Each node should have at least two network interface cards (NIC) to provide a private interconnect for the internode cache fusion traffic and to safeguard against the possibility of network card failure. The private interconnect takes advantage of the performance gains provided by cache fusion. The NICs should have dedicated IP addresses for optimal bandwidth. Alternatively, configure multiple physical NICs as one logical NIC and assign multiple IP addresses to the single logical NIC. Using multiple NICs safeguards against the possibility of network card failure.

Real Application Clusters Preinstallation

Perform the preinstallation steps described in this section before starting the Cluster Setup Wizard. Windows refers to raw partitions as logical drives.

Oracle Cluster File System Preinstallation

Oracle Cluster File System is a shared file system designed specifically for Oracle9i. OCFS eliminates the requirement of linking Oracle datafiles to logical drives and enables all nodes to share a single Oracle home instead of requiring each node to have its own local copy.

The number of partitions used for OCFS affects performance. Therefore, you should create the minimum number of partitions needed for the OCFS option you choose.

• Create two partitions if you are installing OCFS for Both Oracle Home and Oracle Datafiles.

• Create one partition if you are installing either OCFS for Oracle Home Only or OCFS for Oracle datafiles. Do not assign a drive letter to the partitions used by Real Application Clusters, the Cluster Setup Wizard assigns drive letters during configuration.

• Create a logical partition for the voting disk if OCFS for Oracle Datafiles is not be used and assign a symbolic link name to the voting disk.

• Check each node in the cluster to ensure that the partitions are visible on all the nodes and that drive letters are not assigned to the Oracle partitions. If any Oracle partitions have drive letters assigned, then remove them.

• Run Cluster Setup Wizard to install OCFS and Oracle9i clusterware and assign drive letters to the OCFS partitions.

  Minimum size recommendations:

  • OCFS for the Oracle Home - 10 GB

  • OCFS for the Oracle Datafiles - 20 GB

Logical Drive Preinstallation

• Create a logical drive for the voting disk. See Creating Partitions.

• If installing one of the predefined starter databases with Database Configuration Assistant, then create a logical drive for each of the components in table "Logical Drive Disk Sizes for Database Configuration Assistant."

• Run Cluster Setup Wizard to install Oracle9i clusterware to assign symbolic link names, assign a voting disk, and create a cluster.

• Check each node in the cluster to ensure that the partitions are visible on all the nodes and that drive letters are not assigned to the Oracle partitions. If any Oracle partitions have drive letters assigned, then remove them.

Voting Disk Preinstallation

If the datafiles are stored on raw partitions, the voting disk must exist as a logical partition on the shared disk and is required by the Cluster Setup Wizard.

The voting disk stores configuration data for Server Management (SRVM) and is used by Oracle operating system dependent clusterware.

Assigning Symbolic Link Names

Symbolic link names are required in order to use Database Configuration Assistant to install a predefined starter database on logical drives if you are not using Cluster File System for the Oracle Datafiles.

Use one of the following methods to assign symbolic link names:

• Oracle Cluster Setup Wizard

• ImportSYMLinks Utility

• Object Link Manager

Oracle Cluster Setup Wizard

The Oracle Cluster Setup Wizard assists with cluster creation and the addition of nodes to an existing cluster. It also enables you to assign symbolic link names to logical drives.

ImportSYMLinks Utility

The ImportSYMLinks utility is a command line tool that assigns symbolic link names or renames existing symbolic link names.

1. Create a TBL file.

   To...	Do this...
   Modify an existing symbolic link name	Export existing links to a TBL file using the following command: ExportSYMLinks.exe [/f:filename] If /f:filename is not specified, then the default filename, symmap.tbl, is generated in the current working directory. Note: Duplicate links are indented in the symmap.tbl file. All valid unmapped device names are also exported.
   Create a TBL file	A sample ASCII file is located in the following directory on the first component CD:Foot 1 \preinstall_rac\olm\sample.tbl Create a TBL file. Save the file.

   1 This sample file contains symbolic link names associated with raw partitions for a two-node cluster database.

2. Use the following command to import symbolic link mappings:

   ImportSYMLinks.exe [/f:filename]

   For example, ImportSYMLinks.exe /f:c:\temp\mysymlinks.tbl

   where temp is the temporary directory defined in step 1 and filename is the full path and filename of the valid TBL file.

Object Link Manager

Object Link Manager is a GUI tool that assigns symbolic link names or renames existing symbolic link names.

1. Select c:\temp\GUIOracleOBJManager.exe where temp is the temporary directory defined in step 1.

   The Oracle Object Manager window appears.

2. Select the row to update and click any spot within the highlighted row.

   An edit window, with an active blinking cursor, opens in the New Link Name column.

3. Enter the new Link name and choose Enter.

4. Repeat steps 2 and 3 to create additional symbolic link names.

   Note: Do not proceed to step 5 if the edit window is active. Changes will not apply.

5. Select Options > Commit.

Shared Disk Configuration

Before running the Cluster Setup Wizard, you must decide how the shared disk is to be configured. The choice you make, will guide your shared disk preinstall steps. If you are using OCFS for both the Oracle Home and the Oracle Datafiles see "Real Application Clusters Preinstallation"

If you are using OCFS for the Oracle Home or Raw Partitions for Oracle datafiles see "Real Application Clusters Preinstallation" and "Voting Disk Preinstallation".

If you are using OCFS for the Oracle Datafile only, see "Real Application Clusters Preinstallation".

If your are not using OCFS, please read the "Voting Disk Preinstallation".

The Cluster Setup Wizard is used to install Oracle Operating system dependent clusterware layer on Windows Server 2003. The Cluster Setup Wizard can create a new cluster or add a node to an existing cluster. The Cluster Setup Wizard can also configure the shared disks. Table B-2 shows the shared disk configuration options. See "Cluster File System Installed Components and Services" for more information.

Table B-2 Shared Disk Configuration Options

Creating Partitions

Each shared disk used by Real Application Clusters must be configured as a basic disk with a master boot record (MBR) partition style. Real Application Clusters does not support dynamic disks or GUID partition table (GPT) partition style.

Do not use Windows disk administration tools to assign drive letters to partitions in this procedure. Cluster Setup Wizard assigns drive letters to OCFS partitions when you create a cluster.

Opening the Disk Management Tool

The Computer Management window displays disks and volumes in a graphical view and in a list view. View the status of a disk of volume in the Status column of the list view.

1. Choose Start > Settings > Control Panel > Administrative Tools > Computer Management.

   The Computer Management Window appears.

2. Expand the Storage folder and select Disk Management.

   The Disk Management window appears.

Figure B-1 Computer Management Window

Text description of the illustration win2k.gif

Before creating the logical partitions on a disk verify that the disk has the following properties:

• Disk type: Basic

• Partition style: Master Boot Record (MBR)

To view the disk properties:

1. Choose Start > Settings > Control Panel > Administrative Tools > Computer Management

2. Select Disk Management in the left pane.

3. Select the disk from the bottom pane and right-click.

4. Select Properties.

5. In the Properties Disk dialog box, Select the Volumns tab.

If the properties are not correct, use Windows Disk Management to reconfigure the disk.

Creating an Extended Partition from the Disk Management Tool

Before creating the logical drives, first create extended partitions that point to the raw space on the disk. The number of partitions needed depends on the how you configure the shared disk. If more information is needed about creating partitions, refer to the Windows online help from within the Disk Administration tools.

1. Right-click an unallocated region of a basic disk, and click New Partition.

2. Click Next.

3. Select Extended partition in the Select Partition Type page.

4. Click Next.

5. Enter a size for the extended partition in the Specify Partition Size page. Oracle recommends using the maximum value.

6. Click Next.

7. Click Finish.

Creating a Logical Drive from the Disk Management Tool

Before creating the logical drives on a disk verify that the disk is a basic disk and has a Master Boot Record (MBR) partition style:

For each datafile needed in Table B-3, you must complete steps 2 through 11:

1. Right-click the free space in an extended partition, and click New Logical Drive.

2. Click Next.

3. Select Logical Drive option in the Select Partition Type page.

4. Click Next.

5. Set the partition size to correspond to the size defined in the current preinstall step your are executing.

6. Click Next.

7. Select the Do not assign a drive letter or drive path option from the Assign Drive Letter or Path page.

8. Click Next.

9. Select Do not format this partition option from the Format Partition page.

10. Click Next.

11. Click Finish.

    Note: If the Disk Management window is open during any disk management modifications, such as creating symbolic links or adding logical partitions, close and re-open the window to view any changes.

Using Oracle Cluster Setup Wizard

This section describes using the Cluster Setup Wizard.

1. On one node of the cluster, insert the Oracle9i database product CD, and navigate to the \preinstall_rac\clustersetup\ directory and double-click clustersetup.exe. The Welcome page for the Oracle Cluster Setup Wizard appears. Click Next.

2. Select Create a cluster and click Next. The Network Selection page appears.

3. Choose Use Private Network for interconnect and click Next. The Private Network Configuration page appears.
   • If the nodes have a high speed private network connecting them, it should be used as the cluster interconnect. Otherwise, the public network can be selected.

   • If you choose Use Private Network for interconnect, then the Public Network Configuration page appears.

4. Enter the name for the cluster you are creating, and enter the names of the nodes. If a private network interconnect was selected in step 3, enter the public and private names for the nodes; otherwise, enter the public names and choose Next. The Cluster File System Options page appears.

   The following options are available on the Cluster File System Options page:

   • Cluster File System for Both Oracle Home and Oracle Datafiles

   • Cluster File System for Oracle Home Only

   • Cluster File System for Oracle Datafiles

   • No Cluster File System

   If you selected any of the first three options, you must perform the steps in "Real Application Clusters Preinstallation" first.

   Selecting one of the first three options will cause the Cluster Setup wizard to install the Cluster File System driver and supporting applications on to all nodes selected.

5. Choose an option from the OCFS Options page and click Next.
   • If you select No OCFS, then Oracle home and Oracle datafiles are stored on unformatted logical drives. Go to step 8.

   • If you choose Cluster File System for Both Oracle Home and Oracle Datafiles, then two pages appear sequentially: OCFS for Oracle Home Only and OCFS for Oracle Datafiles.

   • If you choose OCFS for Oracle Home Only, then the OCFS for Oracle Home Only page appears followed by the Disk Configuration page for configuring the voting disk.

   • If you choose OCFS for Oracle Datafiles, then the OCFS for Oracle Datafiles page appears.

6. Choose a partition of the required size from the list of available partitions and then choose a drive letter from the Drive Letter list. For the OCFS option that you chose in step 5, the partition and drive letter combination is assigned to the OCFS drive letter for all of the volumes in the cluster.

   For example the voting disk is created in the following format:

   Oracle_datafile_drive_letter:\voting_filename

7. Repeat step 6 for each OCFS volume and click Next.
   • If you chose OCFS for Oracle Home and Datafiles or OCFS for Datafiles in step 5, skip to step 9.

   • If you chose OCFS for Oracle Home in step 5 or No OCFS, then the Disk Configuration page for configuring the voting disk appears because the Oracle database files will not use OCFS.

8. From the Disk Configuration screen, assign a voting disk, labeled as SRVCFG, by highlighting the corresponding row. Optionally, perform one of the following tasks to rename or add a symbolic link:

   To...	Do this...
   Rename a symbolic link	Click Create Oracle Symbolic Links. The Oracle Object Link Manager window appears. Select a row to update from the Symbolic Link column. Enter the new link name. Repeat steps 2 and 3 to rename any additional symbolic link names. Click Apply. When the progress bar at the bottom of the screen stops moving, click Close.
   Create a symbolic link	Click Create Oracle Symbolic Links. The Object Link Manager window appears. Select an empty row from the Symbolic Link column. Enter a link name. Repeat steps 2 and 3 to assign any additional symbolic link names. When the progress bar at the bottom of the screen stops moving, click Close.

9. Choose Next. The wizard checks your cluster interconnect to see if Virtual Interface Architecture (VIA) hardware is detected.
   • If VIA is not detected, then the VIA Detection page appears telling you VIA was not detected and TCP will be used for the clusterware interconnect. Choose Next and skip to step 12.

   • If VIA is detected, then the VIA Selection page appears. Continue to step 10.

10. Choose Yes to use VIA for the interconnect and choose Next. The VIA Configuration page appears. If you choose No, then TCP will be used.

11. Enter the name of the VIA connection and choose Next.

12. The Install Location page is the last page that appears. The default location is SYSTEM_DRIVE\system32\osd9i. Choose Browse to navigate to a different location.

13. Choose Finish. A progress page displays the actions being performed.

Raw Partitions for Datafiles

The voting disk stores configuration data for Server Management (SRVM) and for the Oracle operating system dependent clusterware. Vendor operating system dependent clusterware also requires this disk for Real Application Clusters configuration information.

Real Application Clusters uses logical drives within an unformatted extended partition to store the control, data, and redo log files. Only one extended partition is created for each disk. Oracle Corporation recommends creating the extended partition on an unpartitioned disk and using the entire disk for the extended partition.

Each instance shares a set of unformatted devices on a shared disk subsystem for datafiles. The number and type of raw devices required depends on several factors.

If you plan to use one of the General Purpose, Transaction Processing, or Data Warehouse database configuration types, then you must create a specific number of logical partitions and assign symbolic names to them. The Cluster Setup Wizard does not require these partitions for its installation task, but it can be used to create and assign symbolic links names to partitions. If you decide to use one of the predefined database configuration types refer to "Raw Partitions for Datafiles" and "Using Oracle Cluster Setup Wizard"for more information.

You must also create specific tablespaces using the minimum sizes as listed in Table B-3. When considering size requirements of your disks, remember to account for the initial signature of 1 MB or 2 MBs on each disk that cannot be used for extended partitions. These requirements are the same for both the vendor supplied clusterware layer and Oracle supplied clusterware layer.

Raw Partitions and Sizes

The datafiles, control files, and redo log files must reside on unformatted raw devices on logical drives that reside within extended partitions. The extended partitions point to raw space on the disks. To configure the logical drives, create multiple logical partitions using Windows Disk Management. See the online help for Windows Disk Management for more information.

Table B-3 Logical Drive Disk Sizes for Database Configuration Assistant  

By default, Database Configuration Assistant uses automatic undo management. You should create one Undo tablespace for each instance. Logical drives for Undo tablespaces for all preconfigured database templates should be at least 320 MB. If you use manual undo management, make the RBS logical drive at least 625 MB in size.

Server Parameter File

Database Configuration Assistant uses a logical partition to store the server parameters by default. If you keep this option, you must create one logical partition to hold the server parameters with a file minimum file size 5 MB and symbolic link format db_name_SPFILE. If you do not use this option each instance will have a local copy of the parameters file, and you do NOT need to create the server parameter partition.

Undo Management

Database Configuration Assistant uses automatic undo management by default. Create one Undo tablespace for each instance. Logical drives for Undo tablespaces for all preconfigured database templates should be at least 320 MB with symbolic link format db_name_UNDOTBSinstance_number. If you use manual undo management, make the RBS logical drive at least 640 MB in size with symbolic link format db_name_RBS.

Redo Logs

Database Configuration Assistant will require two logs files for each instance by default. Each redo log files for each instance has a file size of 120 MB and a symbolic link format db_name_REDOinstance_number_thread_number.

Real Application Clusters Management Utilities Overview

There are two sets of utilities. Utilities for raw devices and utilities for Cluster File System Additional disk management utilities are installed by the Oracle Cluster Setup Wizard on all nodes. These tools are not installed if you do not run Oracle Cluster Setup Wizard. Table B-4 describes the disk management utilities.

Table B-4 Raw Devices Disk Management Utilities 

Installing the Raw Devices Management Utilities Manually

If you did not install Oracle9i operating system dependent clusterware using the Oracle Cluster Setup Wizard, then manually install the raw device management utilities.

To manually install the disk management utilities, perform the following tasks on each node of the cluster:

1. Create a temporary directory.

2. From the first component CD, copy the contents of the \preinstall_rac\olm directory to the temporary directory you created.

3. Install Oracle Object Service by entering the following command from the temporary directory you created:

   C:\temp> OracleOBJService /INSTALL

   Note: The Oracle Cluster Setup Wizard automatically creates and starts this service.

4. Set the Oracle Object Service service on each node in the cluster to automatic. Refer to your Microsoft online help for more information about configuring, starting, and stopping services.

If you do not create the database with Database Configuration Assistant, then the number of logical drives you create depends on the number of datafiles, redo log files, and control files you plan to create. However, you must still create a logical drive of 100 MB for the voting disk.

Cluster File System Installed Components and Services

Table B-5 Cluster File System Installed Components 

OcfsUtil Command Summary

OcfsUtil is a command line utility that is used for:

• Changing the cluster name for a given volume.

• Managing the list of nodes configured on a volume.

• Creating, deleting, and reverting node-specific files and directories.

Table B-6 lists the operations performed by OcfsUtil.

Table B-6  OcfsUtil Command Summary

OcfsUtil /c ChangeClusterName /m VolumeMountPoint /n 
NewClusterName

OcfsUtil /c ChangeVolConfig /p /m VolumeMountPoint 
/d NodeName

OcfsUtil /c NodeSpecificFile /o create/delete/revert 
/m MountPoint /p Path /d

OcfsUtil /c NodeSpecificFile /o create /m 
VolumeMountPoint /p FullPath /d

OcfsUtil /c NodeSpecificFile /o create /m MountPoint 
/p Path /d /s

OcfsUtil /c NodeSpecifiFile /o delete /m 
VolumeMountPoint /p FullPath

OcfsUtil /c NodeSpecificFile /o revert /m 
VolumeMountPoint /p FullPath /n NodeName

Formatting a Partition to Add to OCFS

To add a new partition to an existing OCFS, use OcfsFormat to format the partition.

From the command prompt, run:

OcfsFormat /l <driver letter:> /c <Allocation Unit Size>

For example, if the volume is to be given the drive letter O: and an allocation unit size of 4 KB, the command is:

OcfsFormat /l O: /c 4

The Allocation Unit Size reflects the minimum allocation the file system will give to a file. For example, for a 4 KB file, the file system (as shown in the example) will allocate 4 KB of disk space to the file. Once the file grows beyond 4 KB, the file system will give the file another 4 KB from the disk. This small size is optimal for the Oracle home, parameter files, and log files. For the OCFS drive that you select for datafiles, the Allocation Unit Size should be set to 1024 KB minimum.

Transferring the Contents of a Raw Partition to a Standard File System for Backup

Use the Oracle utility OCOPY to copy data to or from a raw partition for both physical partitions and logical drives.

The physical partition and logical drive conventions are not compatible with one another due to the extra block that is skipped for physical raw conventions. This also means you cannot simply do an OCOPY command from a physical disk to a logical drive, as the contents of these partitions are incompatible.

If your database installation uses physical disk conventions with logical drives, Oracle Corporation recommends converting to the logical drive conventions using these steps:

1. Perform a full database export to a (local) file system.

2. Create logical drives and define logical names for these partitions.

3. Re-create the database using Database Configuration Assistant on the new logical drives.

4. Perform the full database import to the newly-created database.

   See Also: Oracle9i Database Platform Guide for Windows for more information

Deleting Oracle Operating System Dependent Clusterware

If you want to deinstall previous versions of Oracle operating system dependent clusterware, use the following steps to manually remove them:

1. Shut down the Oracle database.

2. Stop the operating system dependent clusterware service, OracleCMService9i.

3. Start the registry editor from the command prompt:

   C:\> regedit
   
   

   The Registry Editor window appears.

4. Go to HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\OSD9i.

5. Delete the OSD subkey.

6. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services.

7. Delete the service entry for OracleCMService9i.

8. Delete the osd9i directory under C:\.

9. Repeat the steps on all nodes within the cluster.

10. Restart the computers on which you deleted the keys.

Troubleshooting the Real Application Clusters Installation

This section contains these topics:

• Error Messages

• Performing Cluster Diagnostics

• Terminal Services Client on Windows Server 2003

• Stopping Preexisting Oracle Services

• Mappings Do Not Appear

• Unable to Start a Dedicated Server Process

• Disk Management Cannot Create Logical Drives

• Compatibility Issues for Physical Partitions and Logical Drives

Error Messages

Real Application Clusters Management Tools Error Messages are located in Appendix C of Oracle9i Real Application Clusters Administration.

Performing Cluster Diagnostics

If Oracle Universal Installer does not display the Node Selection page, perform clusterware diagnostics by executing the lsnodes -v command and analyzing its output.

From the \preinstall_rac directory, execute the following:

lsnodes -v

Refer to your clusterware documentation if the detailed output indicates that your clusterware is not running.

Terminal Services Client on Windows Server 2003

Do not use Terminal Services Client with any of the disk management tools. Changes may not be applied.

Stopping Preexisting Oracle Services

You may get the following warning message while using the Cluster Setup Wizard if you have OracleGSDService or OracleServiceSID running on any of the nodes in the cluster you are creating:

The nodes that we are trying to install the software on could not be cleaned 
completely 

Stop these services on all the nodes and then start Oracle Cluster Setup Wizard again.

Mappings Do Not Appear

If mappings do not appear in the Object Link Manager, make sure the Oracle Object Service is started on all nodes in the cluster.

Unable to Start a Dedicated Server Process

Make sure OracleServiceSID and OracleHOME_NAMETNSListener run under the same Windows account with the same user ID.

Disk Management Cannot Create Logical Drives

Most likely, an extended partition was not created. Create the extended partition and the multiple logical drives within the extended partition.

Compatibility Issues for Physical Partitions and Logical Drives

Logical drives defined with physical disk convention names

An Oracle database handles the datafile using the physical disk convention, even though it really is a logical drive. This will not cause any data corruption or loss, as long as the physical disk naming conventions continues to be used. Oracle Corporation recommends that you convert to the logical drive at your earliest convenience.

Using Logical names to represent Partition0.

This poses severe problems, because the Disk Administrator typically writes a signature into the first block of every disk, and consequently the Oracle database may overwrite a portion of the signature with a datafile header.