Users Guide
• Implementing channel redundancy — A virtual disk is channel-redundant when it maintains
redundant data on more than one channel. If one of the channels fails, data is not lost because
redundant data resides on another channel.
NOTE: For more information about channel redundancy, see Channel Redundancy And Thermal
Shutdown.
• Rebuilding data — An failed physical disk that is used by both redundant and nonredundant virtual
disks cannot be rebuilt. Rebuilding a failed physical disk in this situation requires deleting the
nonredundant virtual disk.
• Disk group concept consideration for S110 — Disk grouping is a logical grouping of disks attached to
a RAID controller on which one or more virtual disks are created, such that all virtual disks in the disk
group use all of the physical disks in the disk group. The current implementation supports the
blocking of mixed disk groups during the creation of logical devices.
Physical disks are bound to disk groups, therefore, there is no RAID level mixing on one disk group.
Storage Management Server implements the disk group concept during virtual disk creation. Functionally,
after a group of physical disks is used to create their first virtual disk, unused space in the disk is used only
to expand the virtual disk, or create new virtual disks in the unused space. The virtual disks have identical
RAID level.
Also, existing mixed configuration is not affected. However, you cannot create mixed configurations.
You can read or write to the virtual disks, rebuild, and delete the disks.
You cannot create virtual disks on a set of disks migrated from earlier software RAID versions and
configured with multiple RAID levels.
Related Concepts
Channel Redundancy
Related Tasks
Virtual Disk Task: Reconfigure (Step 1 of 3)
Virtual Disk Considerations For PERC S100, S110, S130, And S300 Controllers
The following considerations apply when creating virtual disks:
• Space allocation — When you create a new virtual disk, the PERC S100, PERC S110, PERC S130, and
PERC S300 controllers allocate the largest area of free space on the physical disks to the new virtual
disk.
• Rebuilding data — If a failed physical disk is used by both redundant and nonredundant virtual disks,
only the redundant virtual disks are rebuilt.
NOTE: For information on controller limitations, see Number Of Physical Disks Per Virtual Disk.
NOTE: When creating virtual disks using software RAID controllers, the information related to the
physical disks linked to the virtual disk is enumerated or displayed on Storage Management after a
short delay. This delay in displaying the information does not cause any functional limitation. If you
are creating partial virtual disks, it is recommended that you provide Storage Management adequate
time between each partial virtual disk creation process.
NOTE: On software RAID controllers, virtual disks can be created only with SATA drives.
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