zfs discuss - Feb 2011 - ZFS utility like Filefrag on linux to help analyzing the extents mapping

Hello All,

I''d like to know if there is an utility like `Filefrag''
shipped with e2fsprogs on linux, which is used to fetch the extents mapping info
of a file(especially a sparse file) located on ZFS?

I am working on efficient sparse file detection and backup through
lseek(SEEK_DATA/SEEK_HOLE)  on ZFS,  and I need to verify the result by
comparing the original sparse file
and the copied file, so if there is such a tool available, it can be used to
analyze the start offset and length of each data extent.


Thanks in advance!
-Jeff

On Wed, Feb 16, 2011 at 8:53 PM, Jeff liu <jeff.liu at oracle.com>
wrote:
> Hello All,
>
> I''d like to know if there is an utility like `Filefrag''
shipped with e2fsprogs on linux, which is used to fetch the extents mapping info
of a file(especially a sparse file) located on ZFS?
Something like zdb -dddd maybe?
http://cuddletech.com/blog/?p=407

-- 
Fajar
>
> I am working on efficient sparse file detection and backup through
lseek(SEEK_DATA/SEEK_HOLE) ?on ZFS, ?and I need to verify the result by
comparing the original sparse file
> and the copied file, so if there is such a tool available, it can be used
to analyze the start offset and length of each data extent.

Hi Fajar,
 
Thanks for your quick response,  just playing it around for a while, it is very
useful to me.

Have a nice day!
-Jeff

? 2011-2-16???10:16? Fajar A. Nugraha ???
> On Wed, Feb 16, 2011 at 8:53 PM, Jeff liu <jeff.liu at oracle.com>
wrote:
>> Hello All,
>> 
>> I''d like to know if there is an utility like
`Filefrag'' shipped with e2fsprogs on linux, which is used to fetch the
extents mapping info of a file(especially a sparse file) located on ZFS?
> 
> Something like zdb -dddd maybe?
> http://cuddletech.com/blog/?p=407
> 
> -- 
> Fajar
> 
>> 
>> I am working on efficient sparse file detection and backup through
lseek(SEEK_DATA/SEEK_HOLE)  on ZFS,  and I need to verify the result by
comparing the original sparse file
>> and the copied file, so if there is such a tool available, it can be
used to analyze the start offset and length of each data extent.