User's Manual

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 Links
Channel Redundancy And Thermal Shutdown
Virtual Disk Task: Reconfigure (Step 1 of 3)
Virtual Disk Considerations For PERC S100, S110, 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, and 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.
Related Links
Number Of Physical Disks Per Virtual Disk
Virtual Disk Considerations On Systems Running Linux
On some versions of the Linux operating system, the virtual disk size is limited to 1TB. Before creating a
virtual disk that is larger than 1TB, you should make sure that your operating system supports this virtual
disk size. The support provided by your operating system depends on the version of the operating system
and any updates or modifications that you have implemented. In addition, you should investigate the
capacity of your peripheral devices to support a virtual disk that is larger than 1TB. For more information,
see your operating system and device documentation.
Number Of Physical Disks Per Virtual Disk
There are limitations on the number of physical disks that can be included in the virtual disk. These
limitations depend on the controller. When creating a virtual disk, the controllers support some stripes
and spans (methods for combining the storage on physical disks). Since, the number of total stripes and
spans is limited, the number of physical disks that can be used is also limited. The limitations on stripes
and spans affect the possibilities for concatenation and RAID levels as follows:
• Maximum number of spans affects RAID 10, RAID 50, and RAID 60.
• Maximum number of stripes affects RAID 0, RAID 5, RAID 50, RAID 6, and RAID 60.
• Number of physical disks in a mirror is always 2. This property affects RAID 1 and RAID 10.
If RAID 50 and RAID 60, you can use a greater number of physical disks than is possible for other RAID
levels. RAID 10 on a SAS controller with firmware version 6.1 can use a maximum of 256 physical disks.
However, the number of connectors on the controller imposes limitations on how many physical disks
can be included in a virtual disk when using RAID 10, RAID 50, or RAID 60. This is because only a limited
number of physical disks can be physically attached to the controller.
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