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Using Standard Configuration

Logical drives are preconfigured on the array before shipment. Read these instructions only if your array is not already configured or if you want to completely remove the existing configuration and start over. If you want to change portions of the existing configuration, refer to the topics under Updating/Changing Your Storage.

Use Standard Configuration Options to quickly configure all the storage attached to an array controller using one RAID level. All you need to specify is the RAID controller, optimization mode, RAID level, and whether you want a standby drive. SANscape then automatically configures the storage for you, creating one or more logical drives, depending on the RAID level and the number of drives available. Write-back cache is selected by default.

(For multiple choices for configuring or reconfiguring logical drives with varying RAID levels and other RAID parameters, see Using Custom Configuration.)

You are able to see the resulting configuration and accept or reject it before it is completed.

CAUTION: Standard Configuration creates one large logical drive. In FC and SATA configurations with large device capacities, the size of the logical drive might exceed the device capacity of your OS. Be sure to check the device capacity limitation of your OS before using Standard Configuration.

CAUTION: Back up any existing data to an external device before configuring the array. Standard Configuration OVERWRITES any existing logical drive configuration. When the existing logical drive configuration is overwritten, all data is effectively erased.

CAUTION: On UNIX systems, before adding new logical drives to existing configurations, you must unmount any file systems that are attached to the array.

  1. Log in as an ssconfig user.
  2. Select the array that you want to configure.
  3. Determine whether the optimization mode of the logical drive is to be Sequential I/O (default) or Random I/O.

    The optimization mode you select determines the maximum number of disks you can include in an array and the maximum usable capacity of a logical drive, total array capacity, and stripe size. Optimization is set in the Cache tab of the Change Controller Parameters window and is set to Sequential by default. For more information on Sequential I/O and Random I/O, and for steps on how to change the optimization mode, see Changing Controller Parameters - Cache tab.

  4. Choose Configuration > Standard Configure. A Standard Configuration Warning message is displayed. Click OK to continue.
  5. The Standard Configuration Options window is displayed. If you are not currently logged in as ssconfig, a login dialog is displayed.

    The options on the window might be disabled, depending on the number of drives available and whether you have a Windows OS or Solaris OS on the server.

    NOTE: In FC and SATA configurations with large device capacities, the size of the logical drive might exceed the device capacity limitation of your OS. Be sure to check the device capacity limitation of your OS before using Standard Configuration.

    The cluster configuration option creates a quorum RAID 5 logical drive (100 Mbyte), and then allocates the remaining capacity over two large RAID 5 logical drives. For this option, three or more physical drives are required.

  6. Verify the server and the controller IDs displayed at the top of the window are correct.
  7. If the server and the controller displayed at the top of the window are not correct for the new logical array, click Cancel to exit the configuration window and return to the main window. Select the appropriate device and select the window again.

  8. Indicate whether you want to use one of the drives as a standby drive.
  9. When you select Use a standby drive, SANscape deactivates the RAID levels that do not use standby drives. (For example, RAID 0 has no fault tolerance; therefore, a standby drive provides no benefit.)

  10. From the RAID levels made available, select the appropriate RAID level for the logical drive you are configuring.
  11. For definitions of the RAID levels, refer to RAID Levels.

    You need a minimum of three drives to use RAID 3 or 5. If you select RAID 1, every logical drive requires at least two physical drives. If you select four or more drives, a logical drive with a RAID 1+0 is created.

  12. (Solaris OS only). If you want the new logical drive to be automatically labeled, which enables the OS to use the drive, click Write a new label to the new LD.
  13. To use the logical drive immediately, select On-line Initialization.

    Because logical drive initialization can take up to several hours, you can choose to initialize a logical drive on-line. On-line initialization enables you to begin configuring and using the logical drive before initialization is complete. However, because the controller is building the logical drive while performing I/O operations, initializing a logical drive on-line requires more time than off-line initialization.

    If you do not select On-line initialization, you can configure and use the drive only after initialization is complete. Because the controller is building the logical drive without having to also perform I/O operations, off-line initialization requires less time than on-line initialization.

  14. Select the Stripe Size.

    Select Default to assign the stripe size per Optimization mode as specified in the default stripe size table shown in Changing Controller Parameters - Cache tab, or select a different stripe size.

    Once the stripe size is selected and data is written to logical drives, the only way to change the stripe size of an individual logical drive is to back up all its data to another location, delete the logical drive, and create a logical drive with the stripe size that you want.

  15. Specify Default, Write-through, or Write-back as the Write Policy for the logical drive.

    The write policy determines when cached data is written to the disk drives. The ability to hold data in cache while it is being written to disk can increase storage device speed during sequential reads. Write policy options include write-through and write-back.

    Using write-through cache, the controller writes the data to the disk drive before signaling the host OS that the process is complete. Write-through cache has lower write operation and throughput performance than write-back cache, but it is the safer strategy, with minimum risk of data loss on power failure. Because a battery module is installed, power is supplied to the data cached in memory and the data can be written to disk when power is restored.

    Using write-back cache, the controller receives the data to write to disk, stores it in the memory buffer, and immediately sends the host OS a signal that the write operation is complete, before the data is actually written to the disk drive. Write-back caching improves the performance of write operations and the throughput of the controller card. Write-back cache is enabled by default.

    NOTE: The setting you specify you specify in the Write Back field on the Cache tab of the Change Controller Parameters window is the default global cache setting for all logical drives. ( See Changing Controller Parameters - Cache tab.

    • Default (default) – Assigns the global write policy that is specified in the Write Back field of the Cache Tab on the Change Controller Parameters window. If the global setting for write policy is changed, automatically changes the write policy for this logical drive.

      The array can be configured to dynamically switch write policy from write-back cache to write-through cache if specified events occur. Write policy is only automatically switched for logical drives with write policy configured to “Default.” See Peripheral Tab for more information about event trigger operations.

    • Write-back – Assigns write-back cache regardless of any changes to the global write policy.

    • Write-through – Assigns write-through cache regardless of any changes to the global write policy.

  16. Click OK. The Confirm Configuration Operation window is displayed showing the new configuration.

  17. Click OK to accept the configuration as indicated; otherwise, click Cancel to return to the console.
  18. (HP-UX OS Only) To ensure the environment is stable and accurate after making configuration changes, you need to run the ioscan -fnC disk command.

    NOTE: If you used System Administrator (SAM) to unmount the file system, make sure it is closed before running the ioscan command.

  19. (IBM AIX OS only) To ensure the environment is stable and accurate after making configuration changes, you need to update the Object Data Manager (ODM) as explained in Updating the Object Data Manager on an IBM AIX Host.

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