Dell MD3000 manual Virtual disk copies, Storage partitions, Flexible, highly scalable storage

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•Use virtual disk high-availability features, such as RAID protection and redundant path failover

•Map snapshot virtual disks and make them accessible to any connected host, and make snapshot data available to secondary hosts by mapping the snapshot to the hosts

•Create up to four snapshots per virtual disk

•Increase the capacity of a snapshot virtual disk

Virtual disk copies

Administrators can use the PowerVault MD3000 and Modular Disk Storage Manager to create exact copies of virtual disks. The target virtual disk copy must be at least the same size as the source virtual disk, and write access to the source virtual disk is blocked during the copy operation. Administrators can specify some set- tings for the virtual disk copy, such as copy pri- ority and read/write permission, before or during the copy operation.

Administrators can use the virtual disk copy feature to perform the following tasks:

•Copy data to larger disks: As storage require- ments for a virtual disk change, administrators can copy virtual disks to a disk group within the same storage array that uses drives with larger capacity than the current drives.

•Copy snapshot virtual disks: Administrators can select snapshot virtual disks as source virtual disks for virtual disk copies, which enables comprehensive backups while helping avoid significant impact on storage array I/O.

•Assign virtual disk copies to hosts: Administrators can directly assign hosts to a target virtual disk, although by default the hosts do not have write access to the virtual disks, and an attempt to write to them results in a host I/O error. Administrators

can enable read/write access by changing the target virtual disk permissions from “Read-Only” to “Read/Write.”

•Recover virtual disks: If a source virtual disk fails, administrators can un-map this failed virtual disk from its host and map its virtual disk copy to the same host.

Storage partitions

A storage partition is a logical entity consisting of one or more virtual disks that can be accessed by a single host or shared among hosts that are part of a host group. The first time administrators map a virtual disk to a specific host or host group, a storage partition is created; subsequent virtual disk mappings to that host or host group do not create another storage partition. LUN masking is implemented using storage partitions.

Administrators can use single storage parti- tions or multiple storage partitions for different purposes. Single storage partitions are useful when only one attached host is accessing all of the virtual disks in the storage array, or when all attached hosts share access to all virtual disks on the storage array; this type of configu- ration requires that all hosts be running the same OS and special software (such as cluster- ing applications) to manage virtual disk sharing and accessibility. Multiple storage partitions are useful when specific hosts are accessing spe- cific virtual disks in the storage array, or when hosts with different operating systems are attached to the same storage array; this type of configuration requires creating a storage parti- tion for each type of host.

Flexible, highly scalable storage

The Dell PowerVault MD3000 is designed to provide a flexible, highly scalable storage system with advanced features such as virtual disk snapshot and virtual disk copy creation.

Deploying this storage system can allow enter- prises to implement highly available shared storage and help them avoid the costs and complexities of internal storage.

Manjusha Gopakumar is a senior engineer ana- lyst in the Test Case Design team at the Dell Bangalore Development Center. She has a bach- elor’s degree in Computer Science from Rajiv Gandhi Technical University.

Vishal Kadam is a senior engineer analyst in the Test Case Design team at the Dell Bangalore Development Center. He has a diploma in Electronics and Communication and is currently pursuing a degree in Information Technology from the University of Mysore. He is a Microsoft Certified Systems Engineer (MCSE), Sun Certified System Administrator (SCSA), and Brocade Certified Fabric Professional (BCFP).

Paul Winston is a test engineer adviser in the Test Case Design team at the Dell Bangalore Development Center. He has a bachelor’s degree in Commerce from Bharathiar University and an advanced diploma in Software Engineering from Aptech. His current interests include implement- ing storage area network, network attached stor- age, and cluster solutions.

QUICK LINK

Dell PowerVault MD3000 User’s Guide: support.dell.com/support/edocs/

systems/md3000

Reprinted from Dell Power Solutions, May 2007. Copyright © 2007 Dell Inc. All rights reserved. Rev. 2.	www.dell.com/powersolutions
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