Virtuoso® For OpenVMS
Description:
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Figure 1: The Virtuoso
Components Flow Diagram
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The software offers virtual-disk capabilities on OpenVMS systems. A virtual disk
appears at the application level as an actual device. Which in reality is a software-maintained
and software-generated representation of a logical device, using an area of memory
and/or a real drive to do the following:
- Reduce the amount of I/O and improve overall-system performance and throughput
- Provide better resource utilization of logical drives
- Achieve improved management and operational effectiveness of logical drives
- Significantly increase the security of data sensitive and/or critical files
The Virtuoso software supports two types of virtual disks---memory-based and drive-based.
Each has its own advantages. By using our software you can tune the attributes of
each to achieve the optimum configuration for your needs. Memory-based procedure
uses an area of physical or paged memory as its working space and treats this area,
as if it were an actual drive. This type is the fastest, since I/O requests are
satisfied, using high-speed memory. Through use of the writeback interval you can
cause all modified pages of an active memory-based drive to be written to a backing
store. The writeback interval enables you to specify in seconds, when modified pages
are written back to their backing store. The interval determines, whether the writeback
is immediate (write through) or periodic. This ensures that the contents of the
virtual memory area in case of a system failure or reboot is saved.
The system provides two kinds of memory-based options---paged memory and
physical (non-paged) memory. Paged-memory allows mapping to a private section that
serves as its backing-store file. Since a VMS process handles the I/O requests,
tuning its working set determines how much of the disk is cached in memory. If your
systems are limited by physical memory or have a requirement for large drive, you
will find this feature helpful.
Physical memory drives use portions of non-paged memory as their work area. Thus,
all blocks of the disk are always in memory. If your systems are not limited by
physical memory, this feature will prove useful to you.
A backing store is the nonvolatile representation of a virtual disk's contents.
Memory-based must use a local file as its backing store. Disk-based virtuals can
use local files (contiguous or noncontiguous), whole or partial volumes, and networked
files or volumes.
The system supports three kinds of drive-based virtual disks---file, volume,
and network. File represents a local virtual disk residing in one or more files.
The file can be contiguous or noncontiguous. Volume represents a virtual disk residing
in one or more partial or complete, physical volumes. Network represents a virtual
disk residing in one or more files or volumes on a remote DECnet node.
Our software can increase the speed of a drive-based virtual disk three ways:
- By caching all or a portion
- By using the Virtuoso Disk-Striping facility
- By specifying contiguous files
It supports all standard OpenVMS QIO functions, normally associated with logical
drives. It allows you to Access, Activate, Deactivate, Modify, Monitor, and List
virtual drives with specific configurations, sizes, and characteristics.
Virtuoso uses standard-DCL syntax, as well as the normal OpenVMS privileges required
for manipulating volumes.
Features:
Caching consists of saving copies of the most frequently accessed sectors in memory.
This increases the effective-transfer rate between your application and the requested
data. Using dynamic caching, the software can automatically extend and/or reduce
the size of the cache, based upon the physical-memory constraints. Static caching
is also available.
In addition caching priorities can be established. Simply instruct Virtuoso to skew
its cache in favor of the device's list of cached files.
Disk striping consists of interleaving the contents of a virtual disk over multiple
backing stores. Interleaving is the alternating use of multiple sectors (usually
one track) on two or more backing stores. Logically, a single drive appears, even
though you use multiple backing stores. Striping helps to prevent the throughput
of a single drive from becoming a bottleneck. By spreading I/O's across multiple
drives, you can use several data paths and heads simultaneously. This limits disk
queuing and improves I/O response time.
To protect your files from intrusion, a Security option is provided. This option
allows you to select a group of users who, depending on VMS job type, may be able
to issue a read and/or write operation. Each user or job type may also be required
to authenticate themselves prior to accessing the virtual disk. The Security facility
also provides an Encryption option for data sensitive information. Encryption is
a process of jumbling or encoding data before it is stored in files. The information
appears illegible to anyone who tries to decipher its meaning without providing
the correct encryption key. When you specify this option at activation time, the
software prompts you for a key to use for encrypting and decrypting the data. Virtuoso
then encrypts all data, stored in virtual devices.
To gain subsequent access to your encrypted data, you must supply the correct encryption
key.
Virtuoso supports the use of Networked Virtual Drives, having a backing store located
on a remote node. The backing store can be a file or a volume. It also supports
a data-compression feature that can significantly reduce the amount of network data
that is transmitted and/or received. For sensitive data, Network Data Encryption
is also available.
The Hardware Error Simulation facility can return specific classes of error information
within designated blocks of data to test your recovery procedures, allowing the
ability to simulate three types of errors. These are parity errors on the basis
of logical-block numbers, device-write-lock errors, and device-offline errors.
Analysis Tools:
The Device Statistics Collector records specified classes of historical statistics
in a log file. These include caching, device, file, and file-control data.
Later, the Report facility selects the raw data from the data-collection file, formats
it, calculates it, and uses it to produce a report. Moreover, you can inquire about
the characteristics of a collection in progress. These include the classes of data
to collect, the beginning and ending times, the sample-interval times, and the specs
for each device.
To create a report, you can take all or only a part of the information, the Device
Statistics Collector has previously logged into the collection file. Thus, you can
report upon whichever class(es) of information you choose.
Virtuoso Monitor provides a window into the activity of a particular virtual drive
or a summary window on a subset of active drives. The program performs three major
tasks. It displays a full status of all disk sets for a given node on any DEC-supported
terminal. It controls the size, location, and the order of the windows. It performs
Add, All, Advance, Backup, Move, Paste, Print, Refresh, Remove, Set, Top, and Unpaste
operations. Thus, you can examine all or part of the current activity.
The different classes of statistics you can monitor with the Monitor program are
caching, cluster, I/O, and striping data. Monitor also allows you to issue most
commands---Access, Activate, Modify, and Deactivate---as well as Spawn and Help
commands from the Monitor prompt.
Minimum Hardware Supported:
The Virtuoso software runs under the OpenVMS operating system under all standard,
VAX and Alpha hardware configurations. Virtual disks require that the drives used
as backing stores be OpenVMS-compatible. Virtuoso fully supports the VMScluster
environment.
Prerequisite Software:
Virtuoso V1.5 operates on any OpenVMS processor, using OpenVMS VAX Version 5.5-2
or later, or OpenVMS Version 6.1 or later.
Optional Software:
SHADOW for OpenVMS Mirroring System
File SHADOW Option for File Shadowing
RemoteSHADOW Option for Intra-Day Business Recovery
Software Installation:
Installation of this product is subject to the terms of the ASCI Standard Software
Product License Agreement. The software is designed to be Customer installable and
uses Compaq's VMSINSTAL facility.
Warranty Information:
This software is sold through ASCI's Software Product License Agreement which warrants
the product for ninety (90) days from the date of purchase. Warranty services include
telephone-remedial support and product upgrades. Additional maintenance services
after the warranty period---as well as consulting or product training---are available
and are separately priced.
Maintenance Information:
After the initial product warranty expires, ASCI offers a twelve-month maintenance
plan. This includes telephone-remedial support, product upgrades, and enhancements,
as they become available. The annual maintenance plan is separately priced.
Ordering Information:
ASCI normally distributes all material via CD- ROM. However, ASCI honors requests
for other magnetic media for a minimal charge, but you must indicate these in your
letter and/or purchase order. The current prices are available upon request. Multi-CPU
and Educational Institutions discounts are available.
This software is licensed using Compaq's License Management Facility (LMF). A Product
Authorization Key (PAK) is required prior to product installation and execution.
Virtuoso consists of a CD-ROM distribution of software (1), Users' Manual (1), Software
Product License Agreement, Software Product Description, and Warranty Registration
Certificate.
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Product Feature/License Table
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Feature
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Base
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Perf
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Stripe
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Secure
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RAM/Page
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X
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Virtual Disks
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X
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Hardware Error Simulation
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X
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|
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Caching
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X
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Striping
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X
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X
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Security
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X
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Encryption
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X
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Collector
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X
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X
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X
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X
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The Virtuoso software consists of magnetic distribution of software (1), User's
Manual (1), Software Product License Agreement, Software Product Description, and
Warranty Registration Certificate.
VIR_190_LIC-License and Distribution Media
VIR_190_RTC-Right-to-Copy License
AD-VIR-190-UM-User's Manual
AD_VIR_190-Addendum and Release Notes
