vSphere Storage - ESXi 5.0 - Documentation - VMware

vSphere Storage
Third-Party Management Applications
You can use third-party management applications in conjunction with your ESXi host.
Most SAN hardware is packaged with storage management software. In many cases, this software is a web
application that can be used with any web browser connected to your network. In other cases, this software
typically runs on the storage system or on a single server, independent of the servers that use the SAN for
storage.
Use this third-party management software for the following tasks:
n Storage array management, including LUN creation, array cache management, LUN mapping, and LUN
security.
n Setting up replication, check points, snapshots, or mirroring.
If you decide to run the SAN management software on a virtual machine, you gain the benefits of running a
virtual machine, including failover using vMotion and VMware HA. Because of the additional level of
indirection, however, the management software might not be able to see the SAN. In this case, you can use an
RDM.
NOTE Whether a virtual machine can run management software successfully depends on the particular storage
system.
SAN Storage Backup Considerations
Having a proper backup strategy is one of the most important aspects of SAN management. In the SAN
environment, backups have two goals. The first goal is to archive online data to offline media. This process is
repeated periodically for all online data on a time schedule. The second goal is to provide access to offline data
for recovery from a problem. For example, database recovery often requires retrieval of archived log files that
are not currently online.
Scheduling a backup depends on a number of factors:
n Identification of critical applications that require more frequent backup cycles within a given period of
time.
n Recovery point and recovery time goals. Consider how precise your recovery point needs to be, and how
long you are willing to wait for it.
n The rate of change (RoC) associated with the data. For example, if you are using
synchronous/asynchronous replication, the RoC affects the amount of bandwidth required between the
primary and secondary storage devices.
n Overall impact on SAN environment, storage performance (while backing up), and other applications.
n Identification of peak traffic periods on the SAN (backups scheduled during those peak periods can slow
the applications and the backup process).
n Time to schedule all backups within the datacenter.
n Time it takes to back up an individual application.
n Resource availability for archiving data; usually offline media access (tape).
Include a recovery-time objective for each application when you design your backup strategy. That is, consider
the time and resources necessary to perform a backup. For example, if a scheduled backup stores so much data
that recovery requires a considerable amount of time, examine the scheduled backup. Perform the backup
more frequently, so that less data is backed up at a time and the recovery time decreases.
28 VMware, Inc.