File - $Quota (Any)

Overview

This file first appeared in Window NT, but wan't used. In Windows 2000, and later, it keeps track of file quotas. Quotas are kept per person and per volume.

Attributes

Layout of the File

$O Index

Flags?

$Q Index

header & repeating group

    sid may be missing (quota flags = default limit => no SID, just padding)
    padding may not be necessary
    index key - xref to which index?
    change time - date/time
    exceeded time - 10/4/01 (not +5 days)
    in the last (null) entry, the padding at 0x0C = 0x02
    

Flags

Notes

Other Information

The index is called $O. This is an index of Owner Ids. It should not be confused with the index of the same name, used by the Metadata File $ObjId.

A file's Owner Id is stored in the $STANDARD_INFORMATION Attribute. The Owner Id can be looked up in $O, to give a Security Id (SID) or looked up in $Q to provide quota information.

    The $Q index contains one entry for each existing user_id on the volume. The
    index key is the user_id of the user/group owning this quota control entry,
    i.e. the key is the owner_id. The user_id of the owner of a file, i.e. the
    owner_id, is found in the standard information attribute. The collation rule
    for $Q is COLLATION_NTOFS_ULONG.

    The $O index contains one entry for each user/group who has been assigned
    a quota on that volume. The index key holds the SID of the user_id the
    entry belongs to, i.e. the owner_id. The collation rule for $O is
    COLLATION_NTOFS_SID.

    The $O index entry data is the user_id of the user corresponding to the SID.
    This user_id is used as an index into $Q to find the quota control entry
    associated with the SID.