The AFS Space Usage Policy Database

Overview

Some AFS Tool Suite scripts (volspot and afs_volspot_check to name two) need to know what suitable sites exist for different types of volumes (a site is a server and partition pair). For example, in your AFS cell, you may have decided on the convention that all user home directory volume names are prefixed with u. (as in u.jblaine). You may also have decided that user home directory volumes should be on the following "sites":

    afsserver1.domain.com       /vicepc
    afsserver2.domain.com       /vicepc
    afsserver3.domain.com       /vicepg
    afsserver3.domain.com       /viceph

Captzeusing your site's volume naming and partition layout information in a single place which can be queried allows you to enforce and check on those policies easily (with or without AFS Tool Suite).

Format

The format of the database (it's a standard text file) is Python ConfigParser format, which is pretty much identical to Windows' INI format. It's pretty simple -- You have 4 possible items in the file:

Blank lines, which are ignored
Comment lines (line begins with a #), which are ignored
Section headings enclosed in brackets, such as [project]
Option=Value lines which belong to the most recently declared section heading (unixname=jblaine for example).

In generic terms, it looks like this:

    # This is a comment and is ignored.
    [section_name1]
    unique_option1=value
    ...
    unique_optionN=value
    
    # The numbers used (1 - N) are not required.  I'm just showing
    # that there can be many, and they have to be unique.
    [section_nameN]
    unique_option1=value
    ...
    unique_optionN=value

AFS Tool Suite recognizes three distinct option types:

regexp - Specifies the regexp for this type of AFS volume. This is used by ATS to make sure that volumes of a certain type are on the defined server:/partition pairs (and only those). The regular expression should match the volume names for this type.
replicated - Define this to be either 'yes' or 'no' (without quotes). This is a flag indicating whether this volume type is expected to have replication set up or not. It is not a flag that will automatically start doing anything on your behalf if set to 'yes', so don't worry. It's only policy information for ATS to use while trying to make sense of your cell and its volumes.
Anything else. Any option found in a section that is not one of the two above will be expected to be a site definition with a value of the format server_name:partition_name. Some valid value examples are srv1.domain.com:/vicepb, ducky.domain.org:g, horsey:/vicepf

Sample Database

    # As you can see below, it's not important that the options
    # be in order or consecutive.  As I said before, they don't
    # even have to have numbers in them, they just need to be unique.
    [root]
    regexp=root.+
    replicated=yes
    site1=hermes:a
    site3=thor:a
    site4=bones:a
    site6=spock:a
    site7=zeus:a

    [afsws]
    replicated=yes
    regexp=.+\.afs\d+[a-zA-Z]+
    site1=hermes:a
    site3=thor:a
    site6=spock:a
    site7=zeus:a
    site8=loki:a

    [apps]
    replicated=yes
    regexp=apps\..+
    site1=hermes:b
    site3=thor:b
    site7=zeus:a
    site8=loki:a

    [user]
    replicated=no
    regexp=u\..+
    site1=hermes:c
    site2=hermes:d
    site4=hera:c
    site7=thor:c

    [proj]
    replicated=no
    regexp=proj\..+
    site1=hermes:f
    site2=hermes:g
    site6=hera:f
    site9=hera:i
    site10=hera:j

    [lang]
    replicated=yes
    regexp=lang\..+\..+(sun|lin|sgi).+
    site1=hermes:l
    site2=hera:l
    site3=thor:l
    site4=bones:l