Users Guide

• 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.
• 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 non-redundant 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 S110 and S130 controllers, if a physical disk (SATA SSD or HDD) is removed from a virtual disk
and the same physical disk is reinserted (hot plug) into the virtual disk instantly, within a fraction of a second, then the
virtual disk state is displayed as Ready and the physical disk state is displayed as Online. However, if the same physical
disk is reinserted after a short delay, then the virtual disk state is displayed as Degraded and the physical disk state is
displayed as Ready.
NOTE: On software RAID controllers, virtual disks can be created only with SATA drives.
Related concepts
Number Of Physical Disks Per Virtual Disk
116
Virtual Disks