Sending Files Larger than 2 gigabytes to XCOM UNIX platforms

Products

• XCOM Data Transport
• XCOM Data Transport - Linux PC
• XCOM Data Transport - z/OS

Issue/Introduction

In the past, sending files larger than 2 gigabytes to UNIX platforms would result in the error "XCOMU0416E Error writing output file: File too large".

This was not a limitation of XCOM. XCOM does not limit the size of a file being transferred. The operating system was limiting the size of a file that can be created. The following UNIX operating systems have added large file support:

RS/6000, AIX release 4.2 and greater,
HP-UX release 10.20 and greater,
Sun Solaris release 2.6 and greater.

Environment

• XCOM™ Data Transport® for z/OS
• XCOM™ Data Transport® for UNIX/Linux PC

Cause

The operating system needs large file support enabled.

Resolution

The following steps need to be performed to take advantage of large file support:

1. The operating system needs large file support enabled.

For AIX you need to specify the Large File Enable Parameter to TRUE when creating your file system. To determine if the file system has Large File enabled, issue the following command:
"lsfs -q file_system_name" and check for the "bf: true" setting.

For HP-UX you need to specify the option largefiles when creating the file system. The default is nolargefiles. To determine if the file system is mounted as largefiles, issue the command:
"fsadm -F hfs /dev/device_name" and check for "largefiles" in the output.

For Sun Solaris you need to specify Large File Support when you mount the file system. The default is to mount as Large File Support unless the nolargefiles mount option is specified. To determine if the drive is mounted as largefiles, issue the command:
"mount" check for "largefiles" in the output .

2) The ULIMIT parameter for the operating system must be set to an unlimited size.
The ulimit command can be used to display the ulimit size and set a user's file size writing limit. To display the file size, issue the command "ulimit". To set the ulimit size to unlimited, issue the command
"ulimit -f unlimited"

For AIX, the FSIZE parameter is the same as ULIMIT. FSIZE can be set as a default and also set specifically for each user. The FSIZE parameter can be found in the /etc/security/limits file. Please contact your systems administrator on making changes to this file.

For HP-UX, the ulimit command is also used for setting file limits for specified resources used by a spawned or child process. For increasing the default file size for a process please see your systems administrator.

For Sun Solaris, the ulimit command sets or reports the file size writing limit imposed on files written by the shell and its child processes. The ?df? command can be run to obtain the maximum possible limits for your system.

3) XCOM Data Transport for UNIX product has been enhanced to support large file options for three platforms. The maintenance releases where this support was first available are:
3.0.99611 for AIX and above
3.0.99613 for Sun Solaris and above
3.0.99617 for HP-UX and above

Not all products at this level and above contain the large file support. Releases were made available both with and without large file support. If you are having problems with files larger than 2 gigs, please contact technical support. The version of the product that you have, even though it is above these release levels may not have the large file support included.