Enabling large file support on UNIX platforms

On operating systems that support large files, Sculptor 5.8.1 supports files with up to 134,217,727 records or 128Gb, whichever is less.

On older UNIX platforms, the maximum size of a file is either 2GB or 4Gb.

Newer UNIX platforms usually support much larger files, typically up to 1Tb. On some versions of UNIX large file support is the default, but on others it must be specifically enabled on the required file system. If it is necessary to create large files, refer to the operating system documentation to determine if large file support is the default and, if not, how to enable it. Since a Sculptor file can become damaged if an attempt is made to increase its size beyond the operating system limit, it is wise to write a small test program to ensure that large file support has been correctly enabled.


  • The following procedure has been tested on UnixWare 7.1.4. Other platforms may require a different procedure.

  • This information is given without warranty and is used entirely at the user’s own risk.

  • Check your operating system documentation to verify that this is the correct procedure and take a full system backup before making these changes.


Log in as root and use the fsadm command to enable large file support on a mounted file system:

fsadm -o largefiles /data

where /data is the filesystem on which large file support is required. This can be the root file system.


Set the ulimit value to unlimited and enable this new limit for all users:

ulimit -f unlimited
defadm login ULIMIT=unlimited


Reset the soft and hard file size resource limits:

/etc/conf/bin/idtune -m SFSZLIM 0x7FFFFFFF
/etc/conf/bin/idtune -m HFSZLIM 0x7FFFFFFF


Rebuild the kernel and reboot the system:

/etc/conf/bin/idbuild -B
cd /
shutdown -g0 -y -i6


Keyed files

Maximum number of records; creating big files

Maximum file size