Storage media is not 100% reliable. Natural disasters, disks
failures, computer viruses and even simple user errors can destroy
months and years of important work. Backups guard against data loss
by copying selected data, applictions or systems to secondary media
located on a tape library or disk array. While backups are often
local, concerns about regional disasters and terrorist activity are
causing many enterprises to employ remote backups -- sending data
to another physical storage facility across a WAN. Backup software
is a crucial part of the backup process, organizing and managing
the flow of data from its source(s) to a suitable backup target.
Today's backup software often includes compression and data
deduplication features to shorten backup windows and optimize the
use of available WAN bandwidth. Encryption and other security
features are also increasingly used to protect data at rest on tape
or disk, and in flight across a LAN or WAN. More recently, content
indexing helps users to quickly locate relevant content based on
search criteria.
But backup software
demands a careful consideration of storage
needs and objectives. Now that you've reviewed the
essential issues involved in any backup
acquisition, this guide focuses on the specific
considerations of backup software products. You'll also find a
series of specifications to help make on-the-spot product
comparisons between vendors like Asigra Inc., BakBone Software
Inc., CA, CommVault, EMC Corp., IBM, Symantec Corp., and
more.
Evaluate backup versus replication. The subtle difference
between backup and replication will have a profound impact on the
way that you protect data -- and the type of software that you
select. Backups typically save files in a proprietary format, so
the backup software must first restore data before it can be
accessed. This makes backups suitable for protecting large volumes
or entire systems that need not be immediately accessible. By
comparison, replication typically makes a 1:1 copy of files in
their native format, so replicated files can be restored on-demand;
even accessed directly from their backup location.
Consider restorability over time. Backups are often
version-sensitive, so it may be difficult to restore older backups
once the backup software is updated. This can prove particularly
troublesome when an organization is faced with a legal discovery
request that demands a search of backups that may span multiple
backup software versions. Before selecting a backup software
platform, be sure to understand how it supports previous and future
backups and interoperability with other manufacturer's backups. It
may be necessary to maintain the older software on a standby backup
server in case it may be necessary to restore an older backup.
Evaluate support for encryption and key management.
Compliance requirements are putting a new focus on data security.
Sensitive corporate data is now routinely encrypted before being
sent to tape or remote disk arrays. If security is a priority,
evaluate the encryption methods available in each backup software
platform such as AES 256. The two main issues with encryption are
performance and key management. The processing overhead required
for encryption generally reduces backup performance, so consider
the effect of encryption on your backup window. Encryption
algorithms also rely on the use of a unique key to encode/decode
the data. Remember that simply changing a key does nothing to
protect backups made with a previous key, so understand how the key
is managed to prevent loss and minimize the possibility of
compromise.
Evaluate WAN support and bandwidth requirements. An
increasing number of data copies are being made to off-site tape or
disk. If you currently move data off-site -- or are considering
off-site backups or replication in the future -- select software
that specializes in support across a WAN and the Internet. Remote
protection software typically has no mimunum bandwidth
requirements, but you'll need to supply enough bandwidth to
complete the backup cycle within the available backup window while
staying within reasonable cost constraints.
Consider the availability of data reduction technologies.
Compression and data de-duplication technologies are used to reduce
backup sizes. Compression replaces repeating data patterns with
much smaller data tokens. Data de-duplication (also called
"single-instance storage) physically saves only one copy of
redundant files or blocks. Both technologies can speed backup
times, reduce the amount of space needed for the backup, and
minimize the use of WAN bandwidth.
Evaluate management overhead and ease of use. When
selecting a new backup or replication software product, consider
the amount of time needed to manage the software. Some amount of
time will be needed to install a new software product or an updated
version, familiarize the IT staff with the new software, and
transfer current policies. It's important for backup administrators
to evaluate any new software and understand the ongoing impact of
any software changes.
The backup software product specifications page in this chapter
covers the following products:
- Asigra Inc.; Asigra Televaulting disk-to-disk (D2D)
software
- Atempo; Time Navigator
- BakBone Software Inc.; NetVault Backup
- BridgeHead Software; HT Backup
- CA; BrightStor ARCserve Backup
- CA; WANSync Data Replication / Data Recovery
Software
- CommVault; Galaxy Backup and Recovery
- EMC Corp.; NetWorker
- EMC Corp.; Retrospect 7.5
- Hewlett-Packard Corp.; OpenView Storage Data
Protector
- IBM; Tivoli Storage Manager (TSM)
- Signiant Inc.; Mobilize for Remote Data Protection
software
- Symantec Corp.; Backup Exec for Windows Servers
- Symantec Corp.; Veritas NetBackup
- Symantec Corp.; Veritas NetBackup 6.0 PureDisk Remote Office
Edition software
- Syncsort Inc.; Backup Express
- Yosemite Technologies Inc.; Yosemite Backup
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