NTFS Filesystem Glossary

access control list (often just ACL)
A security data structure which gives and denys permissions. Unlike the simple Unix user-group-other permissions, an ACL can describe permissions for many users and groups. Many modern Unix systems support this, including AIX, Digital Unix (?), and Solaris (?). Linux support for ACL data is planned for version 2.1, but only in the native ext2 filesystem. [It might be worth investigating the contents of the ACL list. It probably maps straight to the ACL API, with some encoding for permissions and SIDs. If the ACL structure is understood, it might be possible to support NT style access control as a mount option for the Linux driver.]
Infinate logging area
Something contained in $LogFile. It consists of a sequence of 4kB log records.
junction point
Microsoft term for a mount point, available in NT 5.0.
logical sequence number (often just LSN)
A serial number used to identify an NTFS log record.
$LogFile
Special file number 2, the log file. This special file is used to guarantee data integrity in case of a system failure. It has two copies of the restart area and the infinate logging area. The log file is near the center of the partition, just after the second cluster of the boot file. [Better say 'run' than cluster. The boot file usually extends over several clusters at the beginning of the disk, and then has a single run of just one cluster (the copy of the boot sector). Also, isn't it 'infinite'?]
Log record
One 4kB chunk of the infinate logging area. It starts with the magic number 'RCRD' and a fixup, then has undocumented variable length data. [The log record might be further subdivided - I cannot imagine they waste 4kB if they only have to log a few bytes. Custer mentions high level and low level 'records'. High level are: - allocate inode n, - make a directory entry foo in directory m low level are: - modify inode n with the new contents of <1kB>]
$Quota
Special file number 9, with unknown contents. This ought to be for quota information.
Restart area
Two copies of this are in $LogFile. A restart area has the magic number 'RSTR' followed by a fixup and some other data, including three LSNs. A restart area has a pointer into the log area, such as the first and last log records written and the last checkpoint record written. (that is three - now which is which?)