Browse Prior Art Database

AIX File Size Limitation Relief for IBM OnDemand

IP.com Disclosure Number: IPCOM000118601D
Original Publication Date: 1997-Apr-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 113K

Publishing Venue

IBM

Related People

Chen, W: AUTHOR [+5]

Abstract

Disclosed is a solution to relieve AIX* file size limitation when used in conjunction with IBM* OnDemand Download Facility.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 49% of the total text.

AIX File Size Limitation Relief for IBM OnDemand

      Disclosed is a solution to relieve AIX* file size limitation
when used in conjunction with IBM* OnDemand Download Facility.

      For an overview of IBM OnDemand Download Facility, reference
Fig. 1.  The &mvs.  uses Transmission Control Protocol/Internet
Protocol (TCP/IP) protocols to stream data at high speed over a Local
Area Network (LAN) or channel connection from a Multiple Virtual
Storage (MVS) Job Entry Subsystem (JES) spool to the RISC/6000*.  The
&arsd.  on the RISC/6000 receives the data and stores them in files
in file systems for the &arch.  to load into the AFP OnDemand server.

      The &arsd.  has access to up to ten file systems.  The file
systems are specified in the start-up command.
       arsd -pPort# -d/fs1 -d/fs2 -d/fs3 ...

      While receiving data from the host, if a file becomes too large
for a file system to handle, the file "overflows" into a new file
system.  In addition, some checkpoints are taken during transmission
to ensure data integrity.  It also eliminates the need to re-transmit
a large file from the beginning if there is a glitch in the
transmission resulting in data lost.  The design also supports host
operator cancel  and query commands to provide seamless system
management functions.

The following describes the file naming and processing during a file
download transmission:
  o  A host-controlled (user-specifiable) checkpoint interval
      expires.
     -  The &mvs. sends total_bytes_transmitted since the last
         checkpoint to the &arsd. (for it to validate data
         integrity) and reads the acknowledgement.
     -  If the acknowledgement is positive, the &mvs. writes a
         checkpoint to the JES spool.  The checkpoint contains
         (1) the last good record address in the JES spool,
         (2) the number of checkpoint taken for this host
         dataset (including this checkpoint), (3) the
         MVS_assigned_file_name, and (4) running total
         record/page count.  JES and SDSF (Spool Display
         and Search Facility) use the running total to
         satisfy query commands.
          The &arsd. makes the file available for &arch. by
         closing and renaming the file as following:
            MVS_assigned_file_name.ARc.D
        Note: A file is open with a temporary name.  After the
               file is closed it is renamed.
          The "c" is the number of checkpoint taken for this
         host dataset (including this checkpoint).  The "D"
         indicates to the &arch. that all files in the file
         systems with the same MVS-assigned file name and
         suffix of "ARc.n" contain good data.
     -  If the acknowledgement is negative, the &arsd.  closes
       ...