Users Guide

● 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.
● Virtual disk names not stored on controller — The names of the virtual disks that you create are not stored on the controller.
If you reboot using a different operating system, the new operating system may rename the virtual disk using its own naming
conventions.
● 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.
● 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.
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.
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.
Virtual Disks
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