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36 Sun StorageTek SAM Archive Configuration and Administration Guide • Version 4, Update 6, 04/07

Note – Issuing an mv(1) command alters the file name but not the file data, and this

can have ramifications in a disaster recovery situation if you are restoring from

tar(1) files. For more information on disaster recovery, see the Sun StorageTek Storage

Archive Manager Troubleshooting Guide.

A file is selected for archiving based on its archive age, which is the period of time

that has past since the file was last modified. The archive age can be defined for each

archive copy.

Users can change the default time references on their files to values far in the past or

future by using the touch(1) command. This can cause unexpected archiving

results, however. To avoid such problems, the archiver adjusts the references so that

they are always somewhere between the file creation time and the present time.

The archive priority is computed from file property characteristics and from file

property multipliers associated with the archive set. Essentially, the computation is

as follows:

archive-priority = file-property-value x property-multiplier

Most file-property-value numbers are 1 (for true) or 0 (for false). For instance, the

value of the property copy 1 is 1 if archive copy 1 is being made. The values of copy

2, copy 3, and copy 4 are, then 0. Other properties, such as archive age and file size,

can have values other than 0 or 1.

The property-multiplier value is determined from the -priority parameters for the

archive set. Various aspects of a file, such as age or size, can be given values to

determine the archive request’s priority. For more information on the -priority

parameter, see the archiver.cmd(4) man page.

The archive-priority and the property-multiplier values are floating-point numbers. The

default value for all property multipliers is 0.0. The archive request is set to the

highest file priority in the archive request.

The following sections describe the steps taken by the archiver from the initial file

scan to the file copy process.

Step 1: Identifying Files to Archive

There is a separate sam-arfind process for each mounted file system. The

sam-arfind process monitors each file system to determine the files that need

archiving. The file system notifies its sam-arfind process whenever a file is

changed in a manner that would affect its archival state. Examples of such changes

are file modification, rearchiving, unarchiving, and renaming. When notified, the

sam-arfind process examines the file to determine the archive action required.

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US Robotics 7931 Podręcznik Użytkownika Strona 60