Cisco Cisco UCS C24 M3 Rack Server White Paper

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Configure RAID 5 

Create a single RAID 5 drive group with one virtual drive is created using eight 1.2-TB SAS drives. 

1.  In the Integrated Management Controller, navigate to 

Storage and select Cisco 12G SAS Modular Raid Controller. 

2. Select 

Create Virtual Drives from Unused Physical Drives and create a virtual disk using all the available space in the 

RAID 5 drive group (Figure 49).

Figure 49.  Creating a Virtual Disk

3.  Repeat the preceding steps if you have Disk Expansion Pack 2.

Allocate Additional Storage to a VSA for Mirroring

Raw device mapping, or RDM, provides a mechanism that gives a virtual machine direct access to a LUN on the physical 
storage subsystem. 

When you map a LUN to a VMFS volume, vCenter Server creates an RDM file that points to the raw LUN. Encapsulating disk 
information in a file allows vCenter Server to lock the LUN so that only one virtual machine can write to it at a time.

If you use a RAID controller, a RAID array with one or more RAID LUNs or volumes will be created, using the management 
utility supplied with the RAID controller. Each RAID LUN can then be assigned to a local VSA using a raw device mapping. The 
RDM gives the VSA direct access to the device, without the overhead of additional mapping entailed when you use a VMDK. 
In some cases, you may be able to create the RDM using vSphere Web Client; in other cases, you may need to use the ESXi 
console commands to create the RDM, which can then be assigned to the SvSAN as an existing disk drive.

For information about managing the RAID controller, consult the documentation supplied with it. For more information about 
RDMs, consult the vSphere documentation at 

The Cisco UCS C240 M4 supports up to 24 SFF drives. The SvSAN and Cisco UCS C240 M4 architecture supports two disk 
expansion packs, and each disk expansion pack has eight 1.2-TB SAS HDDs and is configured with RAID 5.