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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.
- Log in as an ssconfig user.
- Select the array that you want to configure.
- 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.
- Choose Configuration > Standard Configure.
A Standard Configuration Warning message is displayed. Click OK
to continue.
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.
- Verify the server and the controller IDs
displayed at the top of the window are correct.
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.
- Indicate whether you want to use one of
the drives as a standby drive.
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.)
- From the RAID levels made available, select
the appropriate RAID level for the logical drive you are configuring.
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.
- (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.
- 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.
- 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.
- 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.
- Click OK. The Confirm Configuration
Operation window is displayed showing the new configuration.
- Click OK to accept the configuration
as indicated; otherwise, click Cancel to return to the console.
- (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.
- (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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