Dell PowerVault MD3000 - Manual (Page 35)

Dell MD Storage Array vCenter Plug-in | 35
Figure 32. Create Disk Group Dialog Box
Formatting Virtual Disks
Before you format virtual disks with VMFS datastores, you must plan how to set up storage for the ESX/ESXi
systems, including deciding on the number of virtual disks to use and the size of the virtual disks.
NOTE:
For more information about making virtual disk decisions, including predictive
schemes, adaptive schemes, and disk shares, refer to the iSCSI SAN Configuration Guide:
Using ESX/ESXi with an iSCSI Storage Area Network: Making LUN Decisions in the VMware®
vSphere Online Library.

When you are deciding how to format the virtual disks, keep in mind the following considerations:

Make sure that each virtual disk has the correct RAID level and storage characteristics for applications in
the virtual machines that use that virtual disk. Make sure that each virtual disk contains only one VMFS
datastore.

When multiple virtual machines access the same VMFS datastore, use disk shares to prioritize virtual
machines.

Fewer, larger virtual disks are appropriate for the following reasons:

More flexibility to create virtual machines without asking the storage administrator for more space.

More flexibility for resizing virtual disks, doing snapshots, and so on.

Fewer VMFS datastores to manage.

More, smaller virtual disks are appropriate for the following reasons:

Less wasted storage space.

Different applications might need different RAID characteristics.

More flexibility, as the multipathing policy and disk shares are set per virtual disk.

Use of Microsoft Cluster Service requires that each cluster disk resource is in its own virtual disk.

Better performance because there is less contention for a single virtual disk.