Users Guide

Creating virtual disks
To implement RAID functions, you must create a virtual disk. A virtual disk refers to storage created by a RAID controller from
one or more physical disks. Although a virtual disk may be created from several physical disks, it is seen by the operating system
as a single disk.
Before creating a virtual disk, you should be familiar with the information in Considerations Before Creating Virtual Disks.
You can create a Virtual Disk using the Physical Disks attached to the PERC controller. To create a Virtual Disk, you must have
the Server Control user privilege. You can create a maximum of 64 virtual drives and a maximum of 16 virtual drives in the same
drive group.
You cannot create a virtual disk if:
● Physical disk drives are not available for virtual disk creation. Install additional physical disk drives.
● Maximum number of virtual disks that can be created on the controller has been reached. You must delete at least one
virtual disk and then create a new virtual disk.
● Maximum number of virtual disks supported by a drive group has been reached. You must delete one virtual disk from the
selected group and then create a new virtual disk.
● A job is currently running or scheduled on the selected controller. You must wait for this job to complete or you can delete
the job before attempting a new operation. You can view and manage the status of the scheduled job in the Job Queue page.
● Physical disk is in non-RAID mode. You must convert to RAID mode using iDRAC interfaces such as iDRAC web interface,
RACADM, WS-MAN, or <CTRL+R>.
NOTE: If you create a virtual disk in Add to Pending Operation mode and a job is not created, and then if you delete the
Virtual disk, then the create pending operation for the virtual disk is cleared.
Considerations before creating virtual disks
Before creating virtual disks, consider the following:
● 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.
● 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.
● 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, controllers support a certain number of stripes and spans (methods for combining
the storage on physical disks). Because 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 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 affects RAID 1 and RAID 10.
● Cannot create virtual disks on PCIe SSDs.
Creating virtual disks using web interface
To create virtual disk:
1. In the iDRAC Web interface, go to Overview > Storage > Virtual Disks > Create.
The Create Virtual Disk page is displayed.
2. In the Settings section, do the following:
a. Enter the name for the virtual disk.
b. From the Controller drop-down menu, select the controller for which you want to create the virtual disk.
c. From the Layout drop-down menu, select the RAID level for the Virtual Disk.
Only those RAID levels supported by the controller appear in the drop-down menu and it is based on the RAID levels are
available based on the total number of physical disks available.
d. Select the Media Type, Stripe Size, Read Policy, Write Policy, Disk Cache Policy, T10 PI Capability.
Only those values supported by the controller appear in the drop-down menus for these properties.
e. In the Capacity field, enter the size of the virtual disk.
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Managing storage devices