prealloc - preallocate disk storage
prealloc name size
prealloc preallocates at least size bytes of disk space for an
ordinary file name, creating the file if name does not already exist.
The space is allocated in an implementation-dependent fashion for fast
sequential reads and writes of the file.
prealloc fails and no disk space is allocated if name already exists
and is not an ordinary file of zero length, if insufficient space is
left on disk, or if size exceeds the maximum file size or the file
size limit of the process (see ulimit(2)). The file is zero-filled.
prealloc returns one of the following values upon completion:
0 Successful completion.
1 name already exists and is not an ordinary file of zero
2 There is insufficient room on the disk.
3 size exceeds file size limits.
The following example preallocates 50000 bytes for the file myfile:
prealloc myfile 50000
Allocation of file space is highly dependent on current disk usage. A
successful return does not indicate how fragmented the file actually
might be if the disk is approaching its capacity.
prealloc was developed by HP.
Hewlett-Packard Company - 1 - HP-UX Release 11i: November 2000