| Stephane CHAZELAS 2004-10-18, 7:50 am |
| 2004-10-15, 15:58(-07), Frank Cusack:
[...]
> Actually they can, if the kernel can make that info available. I
> think star has taken advantage of this on some platforms. Hopefully
> Joerg will speak up here.
[...]
From star web site:
* accurate sparse files
star is able to reproduce holes in sparse files
accurately if the OS includes the needed support
functions. This is currently true for Solaris-2.3 to
Solaris-2.5.1
and, as it seems, only for the super-user. From star manpage:
On Solaris-2.3 ... Solaris-2.5.1 there is a special
ioctl() called _FIOAI that allows root to get the
allocation info more efficiently. Other operating sys- tems
lack support to get the real allocation list and force star
to scan the files to look for blocks that only contain null
characters. This may star to assume more holes to be present
than the number that the file really contains.
There seems to be a _FIOAI on Solaris 8, but it's defined as:
#define _FIOAI _FIOOBSOLETE67 /* get allocation info is */
And star doesn't replicate the holes on Solaris 8.
--
Stephane
|