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P R O D U C T P R O F I L E
Copyright
The TANEJA Group, Inc. 2008. All Rights Reserved
87 Elm Street, Suite 900 Hopkinton, MA 01748 Tel: 508-435-5040 Fax: 508-435-1530 www.tanejagroup.com
What To Look For In A SCO VTL
First, you need to understand what your
backup issues are and how you prioritize
them. If you’re like most enterprises, they
will be most of the following: backup
window, RPO, RTO, recovery reliability,
solution cost, and offsite data storage
requirements (whether by tape transport or
replication). Other considerations include
integration issues with your existing data
protection infrastructure, whether you’re
targeting ROBO or data center environments,
and what the quantity of data is that you will
be dealing with over the lifetime of the
solution. Once these issues have been
understood, it’s time to take a look at the
technology options. Over the last several
years, we have talked with hundreds of end
users
that
have deployed SCO VTL
technology, and that input, combined with
our take on the developing trends in data
protection, has led us to define the following
criteria for evaluating SCO VTL solutions:
Performance.
Assuming you want the
data in capacity optimized form, the
operative issue here is how fast you will be
able to complete the backups and get the data
into its capacity optimized form so that it is
ready to be used for any additional
processing, such as tape cloning and/or
replication to a remote site. Whether you
choose an in-line or a post-process approach
may impact backup ingest time, but you still
need to understand the total time required to
ingest and capacity optimize the backup to
ensure that you will have sufficient time to
meet
any
further
backup
processing
requirements.
If your target is to complete daily backup
activities within 8 hours, and you have
roughly 26TB of data that will have to be
transferred each day to perform the backups,
then an in-line solution would need to
process data at about 900MB/sec on a
sustained basis to meet this requirement.
With a post-process solution, you would
need to be able to ingest the backup and
complete the separate SCO processing within
that same 8 hour period - a difficult
challenge. To make this calculation, you’ll
need to ask the vendor about the rate at
which data is capacity optimized during
post-processing.
Scalability.
There are several issues to
consider here. First, understand what the
base capacity of the system is. Capacity
optimization ratios generally vary across
workloads, but the more base capacity is
supported, the more usable capacity will be
supported. Let’s define some terms here.
Base capacity
is the amount of raw capacity
supported after any RAID-based data
protection schemes have been taken into
account.
Usable capacity
refers to the
amount of storage capacity represented after
any applicable SCO technologies have been
applied against base storage capacity. For
example, a system with 50TB of base
capacity, when used with a workload that can
be capacity optimized at a rate of 10:1, can
store up to 500TB of raw data.
Next, understand what kind of capacity
optimization ratios you can expect to
achieve. If vendors offer a capacity planning
tool that can be run against a target workload
to provide an estimate, then take advantage
of this. If at all possible, test several of the
