DRMS: Disaster Recovery Mirroring System

Make sure your business survives -
The question is not IF, it's WHEN !

  • No source code changes
  • Real-time, no-delay data mirroring
  • Hand-off fully automated 24x7 operations
  • No more than 5% performance overhead
  • Power Point presentation
    DRMS Brochure
    User Story (ICA)
    User Story (Tosco)
    ON/2 Implementation
    Stratus Newsletter
    Minimizing data loss

    The Challenge - Recovering Your System Integrity After a Disaster

    Today's sad news is that the disasters of the 20th century seem somehow comforting in the face of disasters from the 21st. We know we can survive the tragedies. The question is how to survive the mess they leave behind.

    What categories do your potential disasters fit into? Natural, man-made, or technology-driven?
    Disasters may come in the form of a server crash, power outage, a cut in communications cables, a fire, or natural disaster. An outage always disrupts your business, causing a loss of productivity, critical information, and loss of revenue. Whatever the cause, you need to minimize data loss by restoring access to your files as quickly as possible and when downed servers are restored, their respective files need to be restored as well.

    How do you protect your data?
    The risks and devastating effects of disasters resulting in computer downtime are obvious, and always present a challenge to any business running critical applications. Business organizations demand 100% fault tolerance and continuous availability of their computing systems. Relying on traditional, full system backups means that any critical data and transactions executed after the last system backup are lost forever. The use of traditional backups also means that data at the remote site always lags behind, so that the remote computers can not be used for online production processing and can only be utilized in the course of a disaster-recovery scenario. For this reason, these vital and expensive resources are idle while the primary computer, in many cases, is over-loaded and suffering from deteriorated performance.

    Do you have a business recovery plan?
    In a world of real time transactions, just-in-time inventory, and supply chain dynamics, losing a phone system might wreak more chaos than a fire in the building. Today, having a Business Continuity Plan is a necessity in the eyes of many insurers, bankers, stakeholders and regulators. Audits of these plans are becoming more commonplace and comprehensive. If you think business continuity means backing up your data and creating redundant systems, then you probably need our help.

    The challenge is to replicate files to a secondary machine, maintaining their availability and protection. If a server goes down, these files are readily accessible and end users can continue working with them.

    DRMS - Protects Your Data - In Real Time, All the Time

    DRMS is a software solution that provides reliable, bi-directional real-time data backup and mirroring over existing Stratus networks. At any given time, all critical remote databases are identical to the primary database, which ensures rapid and reliable application recovery. Networked computers mirror each other, providing a flexible, scaleable load-balancing solution utilizing the full computing capacity of the hardware at both the primary and remote locations. DRMS replicates sequential, fixed, relative and stream files (including transaction-protected files) as well as, one-way-server-queue and message queues. DRMS dynamically detects and replicates newly created critical files so that no configuration changes are necessary. The internal design of DRMS puts great emphasis on protecting the business application and on preserving the primary computer's current performance. DRMS is external to the business application and requires absolutely no application or software changes -- its operation is completely transparent to the user.

    Production Module

    Production and Remote
    databases always identical

    Backup Module

    Click the image to enlarge
    DRMS Components

    Stratus/VOS To Other Platforms - Open Architecture

    DRMS can be used to mirror data into any SQL databases that reside on any platform, via TCP/IP. Based on known data layouts and user-provided templates, DRMS can convert any VOS data into standard text-only formats such as comma-delimited, XML and others. This output is then transmitted to remote ODBC databases or written to local VOS files or queues for further processing.


    IBM Mainframe


    Network Servers


    As a software-only solution, DRMS offers total configuration flexibility and scalability. Any number of modules can mirror each other. The administrator can select and identify critical data files, directories or disks -- all within DRMS' configuration. DRMS can simultaneously mirror critical data in any direction (A-to-B, B-to-A, B-to-C and so on). DRMS supports all VOS platforms and all VOS releases.

    Hands-off operations

    DRMS is designed to run 24x7 without any human intervention. DRMS dynamically manages all aspects of error detection, handling and recovery including alternate routing and communication line switching - always utilizing the entire network bandwidth.

    "The DRMS product has been stable and has worked reliably since we first installed it in August 97. " Anders Carlsson, ICA


    DRMS requires no application changes whatsoever. It is extremely simple to learn, implement, and operate and requires no specific training. The software implementation phase can be completed within a few days, once all critical data files or directories have been identified and listed in DRMS' configuration table (DRMS uses only one TIN file!). DRMS requires no additional hardware as it utilizes existing networks and supports both TCP-IP and X.25 connections.

    "The complete DRMS implementation took about 2 weeks. The installation of the product and the learning curve was done within only one day. Most of the time was spent on analyzing which critical files to mirror, fine-tuning our configuration and running benchmark tests." Anders Carlsson, ICA

    "The product was easy to configure and implement There is nothing more than one table to configure and we were able to do that with simple phone support." Andy Orrock, Tosco Corporation

    Batch Commands

    DRMS replicates VOS internal commands, such as copy_file, move_file, rename, create_file etc. so that any after-hours batch cycles and command-macros are also mirrored accurately at the remote site.

    Monitoring and reporting facilities

    DRMS includes a robust and user-friendly administrator interface. The operator can monitor the system and all aspects of the data mirroring activities - number of I/Os, queuing operations, transaction throughput, processing rate etc. These monitors provide, at all times a great sense of control over the system. DRMS maintains and reports activities both on the system-level and on a per-file basis down to the last minute details of how many I/O operations were made on each critical file broken down by I/O type (write/update/delete etc.)


    Because most of the processing takes place at the target system, DRMS has practically no impact on performance of the primary (sending) computer.

    "Performance of DRMS is terrific - data is mirrored immediately over our 1 MB pipe. We attribute much of the gain in our performance efficiency to the fact that we deployed DRMS to replace a 'homegrown' mirroring solution that was patched together by our OLTP vendor. There is no sign of page faulting. I rate that as very little overhead, considering that we're updating 2-3 files for each transaction and were running at about 14-15 TPS when I took this measurement." Andy Orrock, Tosco Corporation

    "We were also surprised with the results of our performance tests. During normal system load the overhead of DRMS is not noticeable at all, and during peak time (25 transactions/per second) we've measured an overhead of no more than 5%." Anders Carlsson, ICA

    How does DRMS work?

    During run-time, DRMS intercepts all I/O operations performed on files marked by the system administrator as "critical". After the I/O operation is completed, DRMS passes the information to the DRMS Server for transmission to the target system. The corresponding DRMS server on the target computer collects these messages and executes the I/O operation within the remote databases. The only additional work that a mirrored operation requires is sending the message to the DRMS queue. The entire operation is completed with minimal impact on the end-user's program.

    DRMS Features:

    Technical Expertise and Support

    "SoftMark worked closely with Stratus to ensure their systems operated in concert to provide the highest levels of service for Tosco." Stratus Computer news brief, September 1999.

    "The product's reliability and SoftMark's extraordinary responsiveness to our business needs and support questions have made the implementation of our Disaster-Recovery plans an easy, pleasant and trouble-free experience." Anders Carlsson, ICA

    "We rate Application Resources (the distributor of DRMS) and SoftMark (developer/owner) as our best vendors in terms of problem/issue turnaround. Even after-hours, there is no discernible drop-off in resolution speed "). It became very apparent from our discussions that they really understood the issues behind disaster recovery." Andy Orrock, Tosco Corporation

    "SoftMark's technical support and responsiveness is outstanding. Their continued advice and close involvement with our project has made the integration of this product into a very large production system a manageable task." Alex Tulchinsky, AOL

    "SoftMark has provided us with a high level of support and has always been responsive to our business needs." Todd Brown, Sherwood Securities

    Frequently asked questions

    1. What kind of system overhead should I expect?
    2. Overhead depends entirely on user application and mirroring requirements: the rate of I/O, average buffer size and number of critical applications and files. Typically, you should expect not more than 5% overall system overhead.

    3. Is it really that simple?
    4. Not at all! Achieving complete, reliable and efficient data mirroring and planning for Disaster Recovery is not an easy or simple matter. For this reason, keeping-it-simple was our most important objective in the DRMS design:

    5. Do you provide any on-site assistance for DR implementations?
    6. Absolutely! At your request we'll conduct an on-site study for the purpose of setting up a Hot Backup facility for your critical application. We will review all hardware involved, analyze system performance and utilization (CPU, Disk space, I/O activities, Comms., and so on), and application load. We will also review all your management and operation procedures. Our detailed report will provide you with a step-by-step plan for setting up and implementing your Hot Backup and all other application recovery procedures. Typically, the scope of this study goes beyond Hot Backup analysis and includes analysis of system performance and a detailed plan for securing and automating your day to day Stratus operations to reduce the likelihood and risks of system failures.

    7. What happens to mirroring when my communication line is down? What happens to my application?
    8. The product is designed to protect the primary application -- Failed mirroring will have no affect on your application. When communication is restored, DRMS will automatically continue to mirror from the point of failure.

    9. Am I required to run the primary application for the company on the Hot Backup system? If so, what is the main purpose?
    10. Normally, the DRMS Server will perform all I/O on the Hot Backup module, so it is absolutely NOT required to run the application. However, if software licensing is not an issue, there may be cases for executing the application on the backup machine.

    11. What are the hardware requirements? Does the Primary and Hot Backup systems have to be running on the same processor type ?
    12. Absolutely not!

    13. Can I specify files, queues, directories or logical disks?
    14. DRMS has no concept of logical disks. The configuration layer allows you to select files and queues (1-way-server-queues and message-queues). Star-names are also supported, if you need to mirror all files in a specific directory.

    15. I am using two production sites and maintain one backup site for both. Will I be able to mirror the two production systems to the backup site?
    16. DRMS is easily configured to accept input from multiple systems. The only requirement is sufficient bandwidth and resources at the backup site to carry the load.