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83 Setting up the Dell™ DR Series System on Symantec™ NetBackup™ | July 2015
B.1.3 VTL default account summary table
Service
Account
Default Credentials
CLI Modifier
NDMP
ndmp_user
St0r@ge!
ndmp --setpassword
iSCSI
<Appliance Hostname>
St0r@ge!iscsi
iscsi--setpassword
B.2 Managing VTL media and space use
B.2.1 General performance guidelines for DMA configuration
The DR Series system version 3.2 (and later) provides inline VTL deduplication, compression, and encryption
at rest. Backup Applications (such as Dell NetVault, Symantec BackupExec, Symantec NetBackup, etc) should
be configured so that any multiplexing, pre-compression, software side deduplication or encryption is
disabled. Enabling any of these features may adversely affect the space savings and ingest performance of
the DR Series Appliance VTL feature.
Slots and media should be configured so as to accommodate the environment backup requirements. Initially
the logical capacity of a VTL should be no more than twice the physical size of the DR Series Appliance. If the
initial VTL setup is oversubscribed at a higher than a 2-1 ratio without proper planning the DR Series
Appliance could fill up prematurely and cause unexpected system outage. It is highly advisable to configure
the DR Series Appliance VTL such that the media count be made to accommodate the customer’s initial
logical data protection requirements and then media be added as the deduplication statistics become
available to ascertain growth, media and space requirements.
Media Type selection will depend on a number of factors including the DMA used, the backup cycles and
data sources to name a few. As a general rule using smaller tapes is better than using larger tapes so as to
allow for a higher level of control over space usage by backup operations. This also allows for easier handling
in the event of a system running out of physical space as well as the normal data cleanup procedures.
Adding media to an existing DR Series Appliance VTL is painless and should be leveraged to incrementally
add media as needed. Although this may require a higher level of involvement in managing the media usage
it will result in better performance and avoid unplanned outages.
B.2.2 Physical DR space sizing and planning
Various factors such as total data footprint, change rate, backup frequency and data lifecycle policies will
dictate how much physical space will be needed to accommodate the Virtual Tape Libraries within a DR
environment. In addition if other container types are hosted these two must be factored into space
requirement calculations. As a general rule the following can be used as a reference to determine the basic
capacity needed for a given virtual tape library container:
1. Determine existing data set
2. Determine the change rate (Differential)
3. Determine the retention period