Virtual filestore

Any system that is to enable file transfer using FTAM protocols must make its files available to partner systems in a format that is defined by standard (ISO8571). For this purpose a file’s attributes are mapped from the real filestore onto a virtual filestore and vice versa. The virtual filestore thus has no effect on the attributes of the files in the local system, but has only the tasks of transporting file attributes to the remote FTAM system. In the sections below, the criteria for describing a file in the virtual filestore are introduced. The format of the virtual filestore is defined by the FTAM standard. Basically, a distinction is made between three different groups of file attributes:

Kernel group

describes the basic attributes of the files. These are specified when the file is created. They include the file name, information relating to the file structure and file contents, and details of agreed file access rights.

Storage group

covers the storage attributes of files. The storage attributes include the file size, the file availability, the date and time of the last read or write access, as well as identification of the user who initiated this in access.

Security group

defines the security attributes for access protection.

Attributes of the kernel group

The attributes in the kernel group are set when the file is created, and contain the basic information on a file:

file name

contains the file name.

permitted actions

define which actions can be performed for a certain file:

• read file (READ-FILE)

• insert data unit (INSERT-DATA-UNIT)

• replace (overwrite) file (REPLACE-FILE)

• extend file (EXTEND-FILE)

• erase data unit (ERASE-DATA-UNIT)

• read file attributes (READ-ATTRIBUTES)

• modify file attributes (CHANGE-ATTRIBUTES)

• delete file (DELETE-FILE)

The permitted actions also define the method that can be used to access structured files (see also the section "FTAM files").

• forwards (TRAVERSAL)

• backwards (REVERSE TRAVERSAL)

• any (RANDOM)

contents type

Defines the data structure and the method that can be used to access the structured data.

Attributes of the storage group

The attributes of the storage group describe the filestore properties, for example who last accessed the file, the type of access, and when. Some of these properties are automatically modified when the file is read or modified. However, they cannot be modified directly using user commands. You can influence directly modifiable attributes with openFT.

Attribute 1	Definition
storage account *	identifies who is responsible for the file storage costs
date and time of creation	indicates the date and time of creation
date and time of last modification	indicates the date and time of the last modification
date and time of last read access	indicates the date and time of the last read access
date and time of last attribute modification	indicates the date and time of the last attribute modification
identity of creator	identifies the user who created the file
identity of last modifier	identifies the user who last modified the file
identity of last reader	identifies the user who last read the file
identity of last attribute modifier	identifies the user who last modified the file attributes
file availability *	provides information on whether a file is available immediately, or whether it must first be obtained, e.g. from an archive
filesize	describes the storage capacity occupied in the actual filestore. A file can thus differ in size in systems that display file types in different ways. Some filestores assign a multiple of a basic unit, e.g. blocks, for file storage. file size thus specifies a value that does not correspond to the file size
future filesize *	describes the future file size, i.e. possible file size after processing. The initiator can modify the future file size value. As soon as the file reaches the specified file size, the responder can increase the value with or without a warning to the initiator. Alternatively, the responder can reject the modification of a value with an appropriate error message.

¹Attributes marked with * can be modified directly.

Attributes of the security group

The FTAM virtual filestore concept provides a security group for access protection.

Attribute 1	Definition
access control *	indicates the conditions governing access to files. For example, this may include passwords for various types of access (read, insert, replace, extend), or locks that are used to regulate simultaneous access to a file by different users.
legal qualifications *	specify the legal status of the file and its usage. At present, there is no accepted interpretation of this attribute, i.e. its interpretation depends on the particular partner.

¹Attributes marked with * can be modified directly.

The mapping of the file access rights and the mapping of the FTAM attributes to the real file system is described in the manual "openFT (BS2000) - Installation and Operation" and in the manual "openFT (Unix and Windows systems) - Installation and Operation", respectively.