“Advanced Systems Concepts is one of the
first companies to position job scheduling
as a strategic concern, ..." – Michael Dortch, IT R/A, Robert Frances Group
As a result of major business interruptions caused by man and nature, business
managers have come to understand and measure the consequences that disruptions
in access to data can cause to the business. As a result more businesses are
developing and implementing initiatives to find affordable alternatives to keep
their data accessible 24 hours 7 day each week.
RemoteSHADOW by Advanced Systems Concepts, provides business with an easy to
implement, application transparent software solution to ensure your business is
continuously protected, updated and available at a remote contingency site in
the event of a local production site failure. RemoteSHADOW is an affordable
host based solution that protects your data without regard to distance and with
no artificial bandwidth requirements. RemoteSHADOW is available for immediate
deployment on Compaq's Tru64 UNIX and OpenVMS.
How does RemoteSHADOW transport information to my site:
RemoteSHADOW provides two highly reliable methods of transmission to a remote
site or system. With Synchronous communication your data is first written at
the production system and then sent to the remote site to be applied to a
remote device for later use. Once it has been written to the remote system your
application can continue and you can be assured of the highest level of
availability and integrity. However to ensure that production continues with
minimal performance impact there needs to be sufficient bandwidth to
continuously write I/O's at the remote site and to receive a positive
acknowledgement back at the primary system. When the number of write I/O's
exceed the networks ability to receive a timely acknowledgement from the remote
system the production application is forced to slow down and wait. These
situations, which can be caused by a large number of write I/O's and/or
insufficient bandwidth is unacceptable as the production systems performance
levels will be negatively affected and therefore must be avoided.
When your application experiences an unusually high activity level,
RemoteSHADOW's unique Asynchronous Mode of operation provides continuous
availability, locally and remotely, with no production system slowdowns and
without increasing bandwidth or costs.
When should we use RemoteSHADOW's Asynchronous Mode:
Many systems have peak I/O periods of short duration during the course of a
typical day. Unfortunately many replication solutions require that you purchase
bandwidth for these limited peak periods and have it idle for most of the day.
If you would like to minimize the operational cost of bandwidth to deal with
peak periods or potential latency delays caused by transfers over great
distances then RemoteSHADOW's Asynchronous communication is the answer!
RemoteSHADOW's Asynchronous feature always works to stay fully synchronized
with the production systems. However during peak periods, either expected or
unexpected, RemoteSHADOW manages the "peaks" by ensuring that the write I/O's
are applied at the local side and then sent in time ordered sequence to the
remote side. These I/O's are written within a latency period, measured in
seconds, that you decide your business can "tolerate." This dynamic tolerance
can be modified, on an as needed basis, even during the production day to match
bandwidth with peak periods. RemoteSHADOW will queue these I/O's and apply
them, as bandwidth becomes available within your specified time period.
With RemoteSHADOW's Asynchronous Communication method you can limit bandwidth
expense, while ensuring the integrity of the information and still be prepared
to continue your computing operations in the event of a primary site failure.
How do you know how much bandwidth you will need:
RemoteSHADOW comes with an advanced Data Collection Program that can be
installed on your system(s) to measure the write I/O traffic generated for each
disk device during a typical day(s). It will then provide a bandwidth model
that suggests the appropriate bandwidth that would allow for the optimal choice
of synchronization and bandwidth expense that your business and budget allow.
What happens if the Network fails during production:
RemoteSHADOW's Network Restart facility was designed to protect against the all
too familiar "transient network failure." Too often when networks are
interrupted it causes other replication products to fail out the remote site or
cause a split or partitioned environment. Very often these network failures are
for short or relatively short periods of time. Nonetheless they can cause
replicated systems to initiate unnecessary and lengthy network copies. During
these times your business is unnecessarily exposed if a primary site failure
were to occur during a copy operation. RemoteSHADOW avoids this problem and our
customers will back us up! RemoteSHADOW Network Restart feature can "tolerate"
these interruptions by queuing I/O's, in time ordered sequence, at the local
site and then after restarting your network it will apply them and any current
I/O's in the order that they were generated.
RemoteSHADOW's Network Restart feature makes the implementation of disaster
recovery more reliable!
In what operating environments is RemoteSHADOW supported:
RemoteSHADOW is available to protect Compaq's Tru64 Unix and OpenVMS. If your computing platform is not listed
please call for availability.