Re: Perfomance problem backupscript (more details and tests)

Hi,

> > But any _old_ instance of a 32-bit Linux which is running
> > in real life will be unable to accomodate with a filesystem
> > that uses 64-bit file serial numbers.
> 
> Any reasonably recent version of 32-bit Linux has sizeof(ino_t)==8.  You
> have to define _LARGEFILE64_SOURCE to be able to see it, but that is the
> same thing you need for 'open' and 'lstat' to work with large files anyway.

Oh. I shot my own foot when measuring the memory cost of
inode numbers. My program is compiled with LARGEFILE64_SOURCE
and thus gets 64 bit inode numbers, indeed. (I already wondered
why dev_t was 64 and ino_t was 32 bit. Weird default.)

I meanwhile learned that ZFS is a 128 bit filesystem.
Nevertheless i found no hint about the distribution
characteristics of inode numbers. If they are scattered
over the whole 128-bit number space then 64-bit ino_t
is still a problem.
If they increase only if no lower number is ready for
reuse then 64 bit will give us some time to find a
better solution (or to install 256 bit Linux, hehe).


Have a nice day :)

Thomas