Operating System File Size Limits

Different platforms support different maximum file sizes. The limit is imposed by the data type for the value used to seek to a given offset in a file. Older operating systems use a 4-byte signed offset, allowing physical files up to 2 GB. Newer platforms use 4-byte unsigned offsets (4 GB) or 8-byte unsigned offsets (16,000,000 terabytes).

On systems supporting only 4-byte signed offsets:

• Standard c-tree Plus files can grow up to 2 GB in size.
• Extended files can be segmented into multiple physical files up to 2 GB each, allowing a single logical file to grow:
  • to 4 GB using only segmented file support (using segments <= 2 GB each)
  • up to 16,000,000 terabytes using segmented file support and huge file support (using segments <= 2 GB each)

The following platforms are presently limited to 2 GB files:

On systems supporting a 4-byte unsigned offset:

• Standard c-tree Plus files can grow up to 4 GB in size.
• Extended files using huge file support and segmented file support can grow to 16,000,000 terabytes (using segments <= 4 GB each) .

The following platforms fall into this category:

On systems supporting 8-byte offsets:

• Extended format files with huge file support can grow up to 16,000,000 terabytes.
• Segmented file support is optional, but convenient for allocating portions of files to different volumes.
• Standard c-tree Plus files can grow up to 4 GB in size.

The following platforms fall into this category:

Note: The option to support huge files (8-byte offsets) is optional, not default, on some operating systems. Enable huge file support for each volume before creating huge files on that volume under AIX, Solaris, and HP-UX. Use NTFS volumes under Windows NT and 2000.