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HPFS386 and CHKDSK in DASD Limits

IP.com Disclosure Number: IPCOM000112616D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Morris, GL: AUTHOR [+2]

Abstract

The IBM LAN Server provides directory-based, disk space management on HPFS drives, or volumes. This feature has been implemented as "DASD Limits" in HPFS386 - the advanced server/filesystem of LAN Server.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 74% of the total text.

HPFS386 and CHKDSK in DASD Limits

      The IBM LAN Server provides directory-based, disk space
management on HPFS drives, or volumes.  This feature has been
implemented as "DASD Limits" in HPFS386 - the advanced
server/filesystem of LAN Server.

      CHKDSK is a program, included in OS/2*, that repairs drives
formatted for FAT or HPFS.  Because the HPFS format does not natively
support disk space management, the format had to be extended to allow
the LAN Server to provide such support.  Consequently, CHKDSK has to
be extended to support the new format.

      The central issue in the interaction between CHKDSK and HPFS386
can be described as such: How will HPFS386 know when CHKDSK has
repaired the disk since CHKDSK, in such cases, usually modifies the
directory tree?

      When a machine is shut down and then rebooted, the HPFS volume
is in a COHERENT state.  Consequently, CHKDSK will not have to repair
it.  In this case, CHKDSK does not interfere with the status of DASD
Limits on the volume.  There are two cases for DASD Limits where
CHKDSK interacts with HPFS386.

      First, if the volume is not in a coherent state, CHKDSK will
validate the volume.  If any repairs are made, and DASD Limits is in
RUNNING mode, then CHKDSK will change the state of DASD Limits to
RESYNCH.  The RESYNCH mode indicates that the DASD Limits
information, namely the directory size, is not to be trusted.
HPFS386, during its volume mount operation, will detect the RE...