| Barry Margolin 2004-10-18, 8:48 pm |
| In article <slrncn75f3.2ec.stephane.chazelas@spam.is.invalid>,
Stephane CHAZELAS <this.address@is.invalid> wrote:
> 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.
Is there a problem with this assumption? The usual objective is to
optimize disk space. If the new file uses even less space than the
original file, because the original had some real disk blocks that were
all-zero, isn't that even *better* than reproducing the holes accurately?
The main benefit of the ioctl() is that it allows the holes to be
reproduced more efficiently, since star doesn't have to do any scanning.
--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
|