HP ProLiant DL380 G5 Data Protection Storage Server Administration Guide (434184-001, September 2006)

NOTE:

This type of conﬁguration may not apply to all storage servers and serves only as an example.

Through the use of basic disks, primary partitions or extended p artitions can be created. Partitions

can only encompass one LUN. Through the use of dynamic disks, volumes can be created that span

multiple LUNs. The Windows Disk Management utility can be used to convert disks to dynamic and back

to basic, and manag e the volumes residing on dynamic disks. Other options include the ability to

delete, extend, mirror, and repair these elements.

Partitions

Partitions exist as either primary par titions or extended partitions and can be composed of only one basic

disk no larger than 2 TB. Basic disks c a n also only contain up to four primary partitions, or three primar y

partitions and one extended partition. In addition, the partitions on them cannot be extended beyond the

limits of a single LUN. Extended partitions allow the user to create multiple logical drives. These partitions

or logical disks can be assigned drive letters or be used as mount points on existing disks.

Volumes

When planning dynamic disks and volumes, there is a limit to the amount of growth a single volume can

undergo. Volumes are limited in size and can have no more than 32 separate LUNs, with each LUN not

exceeding 2 terabytes (TB), and volumes totaling no more than 64 TB of disk space.

The RAI D level of the LUNs included in a volume must be considered. All of the units that make up a

volume should have the same high-availability characteristics. In other words, the units should all be of

the same RAID level. For example, it would not be a good practice to include both a RAID 1+0 and a

RAID 5 array in the same volume set. By keeping a ll the units the same, the entire volume retains the

same performance and high-availability characteristics, making managing and maintaining the volume

much easier. If a dynamic disk goes ofﬂine, the entire volume dependent on the o ne or more dynamic

disks is unavailable. There could be a potential for data loss depending on the nature of the failed LUN.

Volumes are created out of the dynamic disks, and can be expanded on the ﬂy to extend over multiple

dynamic disks if they are spanned volumes. However, after a type of volume is selected, it cannot be

altered. For example, a spanning volume cannot be altered to a mirrored volume without deleting and

recreating the volume, unless it is a simple volume. Simple volumes can be mirrored or converted to

spanned volumes. Fault-tolerant disks cannot be extended either. Therefore, selection of the volume

type is important. The same per formance characteristics on numbers of reads and writes apply when

using fault-tolerant conﬁgurations, as is the case with controller-based RAID. These volumes can also be

assigned drive letters or be mounted as m ount points off existing drive letters.

The administrator should carefully consider how the volumes will be carved up and what groups or

applications will be using them. For example, putting several storage-intensive applications or groups into

the same dynamic disk set would not be efﬁcient. These applications or groups would be b etter served

by being divided up into separate dynamic disks, which could then g row as their space requirements

increased, within the allowable g rowth limits.

NOTE:

Dynamic disks cannot be used for clustering conﬁgurations because M icrosoft Cluster only supports

basic disks.

File system elements

File system elements are composed of the folders and subfolders that are created under each log ical

storage element (partitions, logical disks, and volumes). Folders are used to further subdivide the

available ﬁle system, providing a nother level of granularity for mana gement of the information space.

Each of these folders can contain separate permissions and share names that can be used for n etwork

access. F olders can be created for individual users, groups, projects, and so on.

HP ProLiant DL380 G5 Data Protection Storage Server