Sidebar: Why OpenVMS Hasn't Faded Away

Computerworld - Performance
OpenVMS can handle 3,000 simultaneous active users and almost 2 million database transactions per minute on Oracle.
Uptime
It's quite normal for VMS cluster uptimes to be measured in years. User after user has verified this.
Clustering
OpenVMS offers shared-everything clustering, i.e., applications running on 96 servers can simultaneously write to the same files on shared disks. If one server goes down, there's no data loss, and the application stays up. Similarly, two physically separate data centers can be part of a single VMS cluster. This feature kept several Wall Street firms in business on Sept. 11, 2001.
Disk Mirroring
Known as volume shadowing on VMS, this feature mimics disk drives for applications using a set of virtual devices. Synchronously mirrored write operations are transparent to users.
Maximum Nodes
OpenVMS can run a maximum of 96 nodes in one cluster, far more than any Unix or Windows-based systems. That equates to over 3,000 processors.
Intersite Distance Limit
The maximum distance allowed between disaster recovery sites is 800 kilometers on OpenVMS, compared with 100 kilometers at best on other systems.
Security
Open VMS is "virtually unhackable," says Ken Farmer of OpenVMS.org. Indeed, at the DefCon 9 Hacker Conference a couple of years ago, OpenVMS beat out Windows NT and XP, Solaris, Linux, BSD and others and was graded as unhackable by the best hackers in the business, according to Farmer.

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