[Lazarus] filesystem timing Linux vs Win

[Mattias Gaertner]

On Sat, 27 Nov 2010 20:14:38 +0100
Florian Klämpfl <florian at freepascal.org> wrote:

> Am 27.11.2010 18:53, schrieb Henry Vermaak:
> > Also, the features of the filesystems
> > are so different, you can't even compare them.  fat and ntfs are stuck
> > in the dark ages compared to ext*.
> 
> Modern NTFS implementations have some really nice and advanced features
> none of the ext* has: snapshoting (saves file server admins a lot of
> time :)) and transactions. I guess especially snapshotting makes ntfs
> slow: CoW semantics simply requires a lot of coping of files and
> fragments probably the disc. I made a similiar experience with btrfs
> (whsich has CoW semantics by default as well) on linux, working with fpc
> on a btrfs partition made fpc really slow. I didn't test further by
> turning off CoW for btrfs, but it might be reason.

Florian, the reading/writing of files seems to be ok under Windows. But
the file access functions are much slower than under Linux (file exists,
date, open, close).
fpc already caches these attributes, but of course it has to read them
every time it starts. It reads over 80 directories. Maybe
someone can check how much time this costs under windows.

BTW, some file systems like zfs under Linux have snapshots too, and the
file access is still as fast as ext*.


> One thing which might help on ntfs: turn off atime, see e.g.
> http://oreilly.com/pub/a/windows/2005/02/08/NTFS_Hacks.html

;)

Mattias