Information Technology Reference
In-Depth Information
federation policies
presentation policies
consistency policies
in order to manage ownership of records independently of storage systems one needs
details of the Data collection
at each remote storage system, an account ID is created under which the
preservation environment stores files
management of roles for permitted operations
management of authentication of users
management of authorization
in order to manage the execution of preservation processes across distributed
resources on further needs:
management of execution state
management of relationships between jobs
management of interactions with remote schedulers
7.9 Emulation
Emulation may be defined as “ the ability of a computer program or electronic device
to imitate another program or device ”[ 79 ]. This is a type of virtualisation but think-
ing more generally one can regard the information one needs to do this as a type of
“Other Representation Information” because such information (including the emu-
lators discussed below) may be needed to understand and, more importantly, to use
the digital object of interest.
There are many reasons for wanting to do this in digital preservation, and several
ways of approaching it. One significant classification of these approaches is whether
the emulation is aimed at one particular programme or device, or whether one aims
at providing functionality which can support very many programmes or devices.
Section 12.2.2.1 discusses the former; an example of the latter is where it may be
sensible to provide the Designated Community with the look and feel of (formerly)
widely used proprietary Access software. In this case, if the OAIS has all the neces-
sary compiled applications and associated libraries but is unable to obtain the source
code, or has the source code but lacks the ability to create the required application
for example because of unavailability of a compiler, necessary libraries or operating
environment, it may find it necessary to investigate use of an emulation approach.
The disadvantage of emulation is that one tends to be stuck with the applications
that used to be available; one tends to be cut off from the more modern applications,
including one's favourite software. The ability to combine data from different eras
and areas is thereby severely curtailed. However this may not matter if one simply
needs to render a digital object, for example display or print a document or image.
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