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New Configuration
The New Configuration
option enables you to customize the logical drive configuration to meet
the specific needs of your environment. You can configure one or more
logical drives with varying RAID levels. You can then add two or more
logical drives (unpartitioned) to a logical volume and divide the logical
volume into a maximum of 32 partitions.
Procedures in this topic include:
The New Configuration
option enables you to customize the logical drive configuration to meet
the specific needs of your environment. You can configure one or more
logical drives with varying RAID levels. You can then add two or more
logical drives (unpartitioned) to a logical volume and divide the logical
volume into a maximum of 32 partitions.
NOTE: On UNIX systems,
if the console locks up during use, you can stop SANscape by typing ssconsole stop. Then close and reopen the window.
The window is displayed again without affecting the agent.
Before
You Use New Configuration
Before you use New Configuration to
create a logical drive or a logical volume for the first time, it is useful
to familiarize yourself with the information contained in the following
steps. Knowing this information ahead of time will ease the process of
creating a logical drive or volume.
- If you have preconfigured logical drives
that you want to delete, see Deleting
a Logical Drive or Logical Volume.
- 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.
- Determine the total number of physical
disks to be included in the logical drive.
If the security of your data is important,
leave remaining disks for standby drives.
NOTE: On systems running the Solaris
OS, if the logical drive is going to be larger than 253 Gbyte, see Preparing
for Logical Drives Larger Than 253 Gbyte.
- Determine whether any standby (spare)
drives will be local or global.
A standby drive is a drive that is marked
as a spare to support automatic data rebuilding after a physical drive
associated with a logical drive fails. For a standby drive to take the
place of another drive, it must be at least equal in size to the failed
drive. Also, the failed drive itself must be from a RAID 1, 3, or
5.
A local spare drive is a standby drive
assigned to serve one specified logical drive. When a member drive of
this specified logical drive fails, the local spare drive becomes a
member drive and automatically starts to rebuild.
A global spare drive does not only serve
one specified logical drive. When a member drive from any of the logical
drives fail, the global spare drive joins that logical drive and automatically
starts to rebuild. Global spares are used in the order in which they
are created.
- Determine the RAID level; SANscape automatically
computes the maximum size logical drive that can be created at that
RAID level.
- Determine whether you want to partition
the logical drive.
A partition is a division of the logical
drive (or logical volume). Partitions enable you to create the appearance
of having separate logical drives (or logical volumes) for file management,
multiple users, or other purposes.
NOTE: Partitioning can be done during
the initial configuration or after the logical drive has been created.
NOTE: Logical drives that have been
partitioned cannot be added to a logical volume.
- Understand the disk capacities displayed
in the New Configuration window.
- Max Drive Size (MB) - displays
the maximum drive size per selected physical disk (total capacity
of each disk).
A smaller logical drive can be created
by decreasing this value. The remainder can be used later by expanding
the drive (as explained in Expanding
the Capacity of a Logical Drive or Logical Volume).
- Available Size (MB) - displays
the total capacity of all disks, which is the total logical drive
or logical volume size.
NOTE: The maximum usable capacity
for a logical drive is equal to the smallest physical size disk. For
example, if you add an 18-Gbyte disk and then add a 70-Gbyte disk
to be part of the logical drive, the maximum usable capacity is 18
Gbyte per drive.
NOTE: Disk capacity is displayed
in powers of 1024. See Device
Capacities for specific device capacities.
- Determine whether the logical drive is
to be part of a logical volume.
NOTE: Logical volumes are unsuited
to some modern configurations such as Sun Cluster environments, and
do not work in those configurations. Use logical drives instead.
NOTE: Logical drives that have been
partitioned cannot be added to a logical volume.
- Determine whether you want to partition
the logical volume.
NOTE: Partitioning can be done during
the initial configuration or after the logical volume has been created.
To Create and Partition a Logical Drive
Using New Configuration
The following steps provide a working example
of creating a new configuration for a new logical drive. Three drives
are selected and configured into a RAID 5 logical drive. A small logical
drive is then created and partitioned.
CAUTION: Back up any existing data
to an external device before using the New Configuration command.
SANscape automatically initializes new logical
drives defined on the array controller.
- Log in as an ssconfig user.
- Select the controller that you want to
configure.
- Make sure that you have selected the appropriate
Optimization mode for your application.
Optimization is set in the Cache tab of the Change Controller
Parameters window. For steps on how to set the Optimization mode,
see Changing Controller
Parameters - Cache tab.
- Choose Configuration > Custom Configure.
- Click New Configuration.
The New Configuration Warning message
box is displayed.
- Click Yes.
- Verify the Server and Controller
displayed at the top of the window are correct.
If the server and the controller displayed
are not correct, click Cancel to exit the New Configuration
window and return to the main window. Select the appropriate disk controller
and reselect New Configuration.
- In the Select disks for Logical Drive
list, select the first disk and click Add Disk.
Proceed to add the next two disks so that
three disks are displayed in the lower list box.
If you make a mistake or change your mind,
select the drive from the drives list and click Remove Disk.
NOTE: Because the logical drive
has not been partitioned yet, the Part Size (MB) and the Available
Size (MB) are equal. A single logical drive is considered to be
a single partition.
NOTE: Mixing SATA and FC disks to
create a logical drive is not supported.
- Select the RAID Level. For this example,
select RAID Level 5.
This applies to all disks in this logical
drive.
In this example, the new logical drive
is composed of three physical disks, totaling 103428 Mbyte, as indicated
in the Available Size (MB) field.
The maximum number of drives per logical
drive for each RAID level is:
- RAID 0 - 36
- RAID 1 - 2
- RAID 1+0 - 36
- RAID 3 or 5 31
For RAID 1, note that if you select four
or more drives, a logical drive with a RAID 1+0 is created.
- Set the Max Drive Size.
The Max Drive Size displays the
total capacity of each disk. A smaller logical drive can be created
by decreasing this value.
NOTE: If you do not change the Max
Drive Size but you do change the Partition Size, SANscape
creates a new partition at the specified partition size. The remaining
logical drive size capacity moves to the last partition. Remaining capacity
can be used later by expanding the drive (as explained in
Expanding a Logical Drive or Logical Volume). The drive capacity
is no longer editable after a partition is created.
- From the Channel and ID list boxes, select
the host channel and ID to which you want the new logical drive mapped.
Host channel connect to host computers
either directly or indirectly through switches or other devices. Select
the appropriate host channel based on the physical connection from
the server to the array.
The ID is a unique address that identifies
the logical drive to the host.
NOTE: If you do not want to map
the logical drive at this time, select Do Not Map from the Channel
list box.
- 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.
NOTE:On-line Initialization does
not apply to logical volumes.
- 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 written to logical drives, the only way to change it is to back
up all data to another location, delete all logical configurations
of drives, reconfigure the logical drive with the stripe size, and
reboot the array.
CAUTION: Only change the stripe
size after you have tested the effects on your application.
- 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).
- This steps depends on what you want to
do next:
- To create another logical drive, click
New LD and repeat Steps 1-11.
- To add this logical to a logical volume
click Add to LV and see To Create Create and Partition
Logical Volumes.
- To partition this logical drive, continue
with the following steps. In this example, a small logical drive is
created and partitioned.
- To create a small logical drive, type
2000 in the Max Drive Size field.
NOTE: In this example, a total of
4000 Mbyte is shown for the logical drive size as opposed to 6000 Mbyte;
because this is a RAID 5 level, you lose the capacity equal to
1 drive (2000 Mbyte) for parity.
- To create a partition, type 1000 in the
Part Size field and click Add Partition.
NOTE: Do not partition a logical
drive if you plan on adding it to a logical volume. Once a logical
drive is partitioned, it cannot be added to a logical volume.
To create multiple partitions of the
same size, click Add Partition as many times as partitions
you want to create. You can also type the partition size in the Part
Size field and multiple (*) it by the number of partitions you
want to create, for example 100*128. Any remaining Mbyte is added
to the last partition.
As you add partitions, the remaining
capacity displayed in Available Size (MB) decreases by the
amount of the partition size.
- (Solaris OS only) If you want the
new logical drive to be automatically labeled, which enables the operating
system to use the drive, click Write a new label to the new LD.
- Click Commit to end the configuration
of the logical drive or New LD to configure another logical drive.
When you click New LD, any available
disks that haven't been used are displayed.
When the logical drive configuration for
this array is complete, click Commit, and then click OK.
The completed configuration is displayed.
NOTE: You cannot change a logical
drive configuration after you click OK.
NOTE: During initialization LD/LV
size is displayed as 0 Mbyte.
- (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
Manager (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 Systems Running IBM AIX Environment.
To Create and
Partition a Logical Volume
A logical volume is composed of two or more
logical drives. The logical volume can be divided into a maximum of 32
partitions. During operation, the host sees a nonpartitioned logical volume
or a partition of a logical volume as one single physical drive.
NOTE: Logical volumes are unsuited
to some modern configurations such as Sun Cluster environments, and do
not work in those configurations. Use logical drives instead.
- Create a logical drive as described in
Steps 1-14 above.
NOTE: Do not partition the logical
drive that you are adding to the logical volume. A logical drive that
has been partitioned cannot be added to a logical volume.
- Before you click Commit, to add
the logical drive to a logical volume, click Add to LV.
The logical drive is added to the LV
Definition box. The total size of the logical volume is displayed
in the Available Size (MB) field.
NOTE: Because the logical volume
has not been partitioned yet, the Part Size (MB) and the Available
Size (MB) are equal. A single logical volume is considered to be
a single partition.
NOTE: Mixing SATA and FC logical
drives to create a logical volume is not supported.
- To create another logical drive to add
to the logical volume, click New LD.
- Create the logical drive and add it to
the logical volume by clicking Add to LV.
Repeat this step for every logical drive
you want to ad to the logical volume.
- To create a partition, type the partition
size in the Part Size field and click Add Partition.
To create multiple partitions of the
same size, click Add Partition as many times as partitions
you want to create. You can also type he partition size in the Part
Size field and multiply (*) it by the number of partitions you
want to create, for example 100* 128.
As you add partitions, the remaining capacity
displayed in Available Size (MB) decreases by the amount of the
partition size.
- When you have finished adding logical
drives to the logical volume, to create another logical volume or an
individual logical drive, click Commit LV.
When you have finished creating logical
volumes and do not want to create an individual logical drive, click
Commit.
NOTE: When you have finished creating
logical volumes and want to exit the New Configuration window,
if you accidentally click Commit LV instead of Commit,
you still have to create another logical drive; otherwise, you have
to click Cancel and configure the logical volume again.
- (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
Manager (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 Systems Running IBM AIX Environment.
To Clear a Configuration
If at any time during the configuration process
in the New Configuration window you are dissatisfied with the configuration,
you can clear it.
- Click Clear to remove all physical
and logical drives from the display.
- Either click New LD to define a
new logical drive, or click Commit.
- When you click Commit, a warning
prompt is displayed; click OK.
SANscape initializes the entire configuration
on the selected array controller.
NOTE: Host LUNs are automatically
mapped after logical drives have completed the initialization process.
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