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gpfs_prealloc() Subroutine
Exceptions
None.
Error status
EACCES The file is not opened for writing.
EBADF The file descriptor is not valid.
EDQUOT A disk quota has been exceeded
EFBIG The file has become too large for the file system or has exceeded the file size as defined
by the user’s ulimit value.
EINVAL The file descriptor does not refer to a GPFS file or a regular file; a negative value was
specified for StartOffset or BytesToPrealloc.
ENOTREADY The file system on which the file resides has become unavailable.
ENOSPC The file system has run out of disk space.
ENOSYS The gpfs_prealloc() subroutine is not supported under the current file system format.
Examples
#include
#include
#include
#include
int rc;
int fileHandle = -1;
char* fileNameP = "datafile";
offset_t startOffset = 0;
offset_t bytesToAllocate = 20*1024*1024; /* 20 MB */
fileHandle = open(fileNameP, O_RDWR|O_CREAT, 0644);
if (fileHandle < 0)
{
perror(fileNameP);
exit(1);
}
rc = gpfs_prealloc(fileHandle, startOffset, bytesToAllocate);
if (rc < 0)
{
fprintf(stderr, "Error %d preallocation at %lld for %lld in %s\n",
errno, startOffset, bytesToAllocate, fileNameP);
exit(1);
}
Location
/usr/lpp/mmfs/lib/libgpfs.a for AIX, /usr/lpp/mmfs/lib/libgpfs.so for Linux
334 GPFS: Administration and Programming Reference