Dell MD3000 - Manual (Page 3)

connected to a host using Ethernet, or a
combination of the two
• Display configuration information, add and
remove storage arrays, and manage Simple
Network Management Protocol (SNMP) and
Simple Mail Transfer Protocol (SMTP) alert
notifications
Figure 5 shows a script file called sample.scr
that creates a 2 GB RAID-5 virtual disk called
“Test” and sets its parameters. To run this script
file from the CLI, administrators would enter the
following command (where ipaddress is the
IP address of the storage enclosure):
smcli ipaddress -f sample.scr;
Advanced features of the Dell
PowerVault MD3000
Administrators can use the PowerVault MD3000
and Dell Modular Disk Storage Manager to create
virtual disk snapshots, virtual disk copies, and
storage partitions. Virtual disk snapshot creation
and virtual disk copy creation are premium fea-
tures that must be purchased and enabled
separately.
Virtual disk snapshots
Snapshots are persistent point-in-time images
of a specific virtual disk that help eliminate the
application downtime traditionally required to
create system backups. They typically use less
disk space and take less time to create than a
physical copy.
Snapshots are implemented using the
copy-on-first-write method: when virtual disk
data needs to be modified, the original data is
copied to the virtual disk snapshot cache before
it is modified. The virtual disk on which the
snapshot is based—the source virtual disk—
must be a standard virtual disk in the storage
array. Snapshots are typically created so that
software such as a backup application can
access them while the source virtual disk
remains accessible to hosts.
Modular Disk Storage Manager supports
application-aware snapshots, which are recom-
mended for transaction-based applications
where all transaction operations must be com-
pleted for transactions to be valid. Application-
aware snapshots coordinate with the application
using the virtual disk to help ensure the consis-
tency of snapshot data with application data.
Once the snapshot has been created, the snap-
shot engine signals the application to resume
normal processing. Microsoft Volume Shadow
Copy Service (VSS) enables the creation of these
snapshots.
Administrators can use the virtual disk
snapshot feature to perform the following
tasks:
• Create a complete image of data on a virtual
disk at a particular point in time
• Provide quick, frequent, nondisruptive
backups
• Test new versions of a database system with-
out affecting actual data
• Enable snapshot virtual disks to be read,
written, and copied
Figure 4. Dell Modular Disk Storage Manager GUI
Figure 5. Sample script for the Dell Modular Disk Storage Manager CLI
//sample.scr
create virtualDisk diskGroup=1 RAIDLevel=5 userLabel="Test" owner=0
segmentSize=16 capacity=2GB;
set virtualDisk["Test"] mediaScanEnabled=false;
set virtualDisk["Test"] consistencyCheckEnabled=false;
set virtualDisk["Test"] modificationPriority
=high;
reprinted from Dell Power Solutions, May 2007. Copyright © 2007 dell inc. all rights reserved. rev. 2.
Storage
DELL POWER SOLUTIONS | May 2007
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