User's Manual

Virtual Disks 213
virtual disks can result in pockets of free space residing in various locations
on the physical disks. When you create a new virtual disk, the controller
must decide which free space on the physical disks to allocate to the new
virtual disk. The PERC 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, and 4e/Di
controllers look for the largest area of free space and allocate this space to
the new virtual disk.
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SCSI limitation of 2TB —Virtual disks created on a PERC 4/SC, 4/DC,
4e/DC, 4/Di, 4e/Si, 4e/Di, and SAS 5/iR controller cannot be created from
physical disks with an aggregate size greater than 2TB. This is a limitation
of the controller implementation. For example, you cannot select more
than 30 physical disks that are 73GB in size, regardless of the size of the
resulting virtual disk. When attempting to select more than 30 disks of
this size, a pop-up message is displayed that indicates that the 2TB limit
has been reached, and that you should select a smaller number of physical
disks. The 2TB limit is an industry-wide SCSI limitation.
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Expanding virtual disks —You can only use the Reconfigure task to
expand a virtual disk that uses the full capacity of its member physical
disks. For more information, see Virtual Disk Task: Reconfigure (Step 1 of
3).
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Reconfiguring virtual disks —The Reconfigure task is not available when
you have more than one virtual disk using the same set of physical disks.
You can, however, reconfigure a virtual disk that is the only virtual disk
residing on a set of physical disks. For more information, see Virtual Disk
Task: Reconfigure (Step 1 of 3).
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Virtual disk names not stored on controller —The names of the virtual
disks that you create are not stored on the controller. This means that if
you reboot using a different operating system, the new operating system
may rename the virtual disk using its own naming conventions.
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Creating and deleting virtual disks on cluster-enabled controllers —
There are particular considerations for creating or deleting a virtual disk
from a cluster-enabled controller. Review Creating and Deleting Virtual
Disks on Cluster-enabled Controllers before attempting to create the
virtual disk.