HP RMS Journaling for OpenVMS

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Software

Product

Description

PRODUCT NAME: HP RMS Journaling for OpenVMS SPD 27.58.16

Note: This is the Software Product Description (SPD)

for the following products:

• HP RMS Journaling for OpenVMS for Integrity

servers, Version 8.3

• HP RMS Journaling for OpenVMS for Integrity

servers, Version 8.2-1

• HP RMS Journaling for OpenVMS for Integrity

servers, Version 8.2

• HP RMS Journaling for OpenVMS Alpha, Version 8.2

• HP RMS Journaling for OpenVMS VAX Version 7.3

Except where speciﬁcally noted, the features described

in this SPD apply to all tnese products. The license and

part number information is architecture speciﬁc. Please

refer to the Ordering Information section of this SPD for

further details.

DESCRIPTION

RMS Journaling for OpenVMS helps maintain the data

integrity of OpenVMS RMS ﬁles and protects this ﬁle

data from becoming lost or inconsistent due to various

failure scenarios.

RMS Journaling for OpenVMS provides the following

three methods of journaling:

• After-image (AI) journaling allows you to redo a se-

ries of modiﬁcations to a ﬁle. This type of journaling

helps recover lost or corrupted ﬁles. After-image re-

covery restores the contents of the ﬁle from the point

of the latest backup copy of that ﬁle.

• Before-image (BI) journaling allows you to undo a se-

ries of modiﬁcations to a ﬁle. This type of journaling

returns the ﬁle to a previous known state. This is

useful when a ﬁle is updated with erroneous data.

• Recovery unit (RU) journaling helps maintain trans-

action integrity, where a transaction consists of a

group of related operations that must be atomic. That

is, either all of the operations complete in their en-

tirety, or none of the operations complete. This type

of journaling helps prevent data from becoming in-

consistent due to the incomplete execution of a trans-

action.

Journaling is applied on a ﬁle-by-ﬁle basis. A ﬁle can

be marked for AI, BI, or RU journaling, or any combina-

tion of these methods. Within a given application, any

combination of journaling methods can be used.

RMS Journaling for OpenVMS stores the information

necessary for data recovery in ﬁles known as journals.

Multiple ﬁles can use the same journal.

RMS Recovery Unit Journaling and DECdtm

Transactions

Transactions are deﬁned and managed using the

DECdtm transaction services available within Open-

VMS. An RMS recovery unit is a set of RMS record

operations, performed in the context of a single process,

that is part of a transaction coordinated by DECdtm ser-

vices. RMS recovery units are started automatically by

RMS, and RMS recovery units are committed or aborted

along with the transaction of which they are a part.

RMS Journaling for OpenVMS functions as a resource

manager in transactions that use DECdtm services.

DECdtm services are implemented using a two-phase

June 2006

Summary of content (6 pages)

PAGE 1
Software Product Description PRODUCT NAME: HP RMS Journaling for OpenVMS Note: This is the Software Product Description (SPD) for the following products: • HP RMS Journaling for OpenVMS for Integrity servers, Version 8.3 • HP RMS Journaling for OpenVMS for Integrity servers, Version 8.2-1 • HP RMS Journaling for OpenVMS for Integrity servers, Version 8.2 • HP RMS Journaling for OpenVMS Alpha, Version 8.2 • HP RMS Journaling for OpenVMS VAX Version 7.
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HP RMS Journaling for OpenVMS SPD 27.58.16 commit protocol. RU journaling supports both a onephase and a two-phase commit protocol. RMS Journaling for OpenVMS is enabled on a file-byfile basis. Files marked for AI, BI, and RU journaling are enabled by using qualifiers to the DCL command SET FILE. You can use any combination of qualifiers with a particular SET FILE command or series of SET FILE commands.
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HP RMS Journaling for OpenVMS SPD 27.58.16 No user intervention is required to roll back a recovery unit that is incomplete. The rollback of an incomplete transaction is started and completed automatically the next time a user attempts to access the file. Under some circumstances, an application that uses only AI journaling can take proactive measures to guard against data inconsistencies after process deletions or system failures.
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HP RMS Journaling for OpenVMS SPD 27.58.16 (SPD 25.01.xx) or the HP OpenVMS for Alpha and Integrity Servers Version 8.3 Software Product Description (SPD 82.35.xx), and the OpenVMS Cluster Software Software Product Description (SPD 29.78.xx) list any special hardware required by this product.
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HP RMS Journaling for OpenVMS SPD 27.58.16 © 2006 Hewlett-Packard Development Company, L.P. Confidential computer software. Valid license from HP required for possession, use or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor’s standard commercial license. The information contained herein is subject to change without notice.
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