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Contemplating VAX to Alpha Migration
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So you are considering migrating from VAX to Alpha but hesitate? You have many questions about it with no answers in sight. This article should help to address some of those questions and ease your mind.
THE END OF Rdb & DBMS PERFORMANCE PROBLEMS
The time for AlphaServers has come! Yes, you may be able to squeeze some additional performance from your VAX systems…but if you really want your applications to run fast, then your plans must include Alphas. These machines are fast, reliable and very cost effective. Fortunately, the migration path may be easier than you think, and your savings on maintenance may even make the bean-counters smile. And to top that, your performance problems may be over!
MIGRATION IS EASY
VMS
is VMS (for what it is worth, VMS = OpenVMS). OpenVMS on the VAX is really
the same operating system as OpenVMS on the Alpha. No database changes
are required to your Rdb and CODASYL DBMS databases to run on an
Alpha (the same database can be run on either an Alpha or a VAX, or
both). This is important, because I believe that a lot of people are
afraid of the word migration, and have avoided the move because
they fear massive program changes, a database migration or an unfamiliar
environment. The process of migration from VAX to Alpha is more similar to
“move” than “migration.” Executables (.EXE files) are different,
so your program will need to be recompiled and linked.
“NO-MOVE” MIGRATION
It is possible to migrate from VAX to Alpha without moving any of your databases or user files. To perform this style of a migration you must have a heterogeneous cluster (a cluster with both VAXes and Alphas) and you must create a new directory structure for the Alpha executables. Recompile and link your applications on the Alpha and you are ready to run on the Alpha. This approach has the benefit of avoiding the need to move files and provides access to your application (and data) from the old VAX environment. However, this method fails to realize all of the benefits of your new hardware – a super-fast I/O bus, faster controllers and disk drives. If you are still on slow disks, slow controllers and a slow bus…your performance may still suffer.
“FAST-MOVE” MIGRATION
Another approach to your migration is to move the entire system to the new architecture at one time. The benefit of this approach is that you can maximize your application performance by utilizing all new technology. Believe it or not, this can be done with minimal downtime when carefully planned. The key to this method is to use Software Concepts International’s hot-standby solution to maintain a synchronized copy of the production database on the Alpha prior to the migration. By using SCI’s hot-standby solution during a “fast-move migration,” a 50GB database can be moved with only minutes of downtime! SCI has also helped customers move non-database files with minimal downtime by utilizing a combination of full and incremental backups and restores over the network.
SUCCESSFUL MIGRATIONS
SCI
has helped a number of large customers worldwide move their WorkStream and
MANMAN
applications from VAX to the Alphas. During most of these migrations,
customers used our hot-standby solution since this provides a very fast
migration and allows them to immediately take advantage of the new
hardware.
To see how your current VAX systems compare in performance to
the Alpha systems, visit
Compaq's WEB site: http://www.compaq.com/alphaserver/performance/perf_tps.html.
The numbers are truly impressive!