the following patch is needed to report correct disk space values,
it's likely to also be needed for other OS.

— src/libs/zbxsysinfo/openbsd/diskspace.c.orig Tue Oct 28 13:24:30 2008
+++ src/libs/zbxsysinfo/openbsd/diskspace.c Tue Oct 28 13:56:04 2008
@@ -42,22 +42,22 @@ int get_fs_size_stat(const char *fs, zbx_uint64_t *tot

#ifdef HAVE_SYS_STATVFS_H
if (total)

• *total = (zbx_uint64_t)s.f_blocks * s.f_frsize;
  + *total = (zbx_uint64_t)s.f_blocks * (s.f_frsize / 1024.0);
  if (free)
• *free = (zbx_uint64_t)s.f_bfree * s.f_frsize;
  + *free = (zbx_uint64_t)s.f_bfree * (s.f_frsize / 1024.0);
  if (used)
• *used = (zbx_uint64_t)(s.f_blocks - s.f_bfree) * s.f_frsize;
  + *used = (zbx_uint64_t)(s.f_blocks - s.f_bfree) * (s.f_frsize / 1024.0);
  if (pfree)
  *pfree = (double)(100.0 * s.f_bfree) / s.f_blocks;
  if (pused)
  *pused = (double)(100.0 * (s.f_blocks - s.f_bfree)) / s.f_blocks;
  #else
  if (total)
• *total = (zbx_uint64_t)s.f_blocks * s.f_bsize;
  + *total = (zbx_uint64_t)s.f_blocks * (s.f_bsize / 1024.0);
  if (free)
• *free = (zbx_uint64_t)s.f_bfree * s.f_bsize;
  + *free = (zbx_uint64_t)s.f_bfree * (s.f_bsize / 1024.0);
  if (used)
• *used = (zbx_uint64_t)(s.f_blocks - s.f_bfree) * s.f_bsize;
  + *used = (zbx_uint64_t)(s.f_blocks - s.f_bfree) * (s.f_bsize / 1024.0);
  if (pfree)
  *pfree = (double)(100.0 * s.f_bfree) / s.f_blocks;
  if (pused)