[lustre-discuss] FIEMAP support for Lustre

[Dilger, Andreas]

Of historical interest is that FIEMAP was actually developed for Lustre first, and was then added to the other filesystems when we pushed it upstream.  The older FIBMAP interface just wasn't scalable enough to handle the large files that Lustre is using.

Unfortunately, because the Lustre client was not in the kernel at the time, some of the FIEMAP features that Lustre uses are not included in the upstream FIEMAP (e.g. device reporting and device-ordered output).

You can use filefrag from any Lustre-patched e2fsprogs to output the layout for multi-striped files, or vanilla filefrag for single-striped files.

Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division

On 2015/08/24, 9:57 AM, "lustre-discuss on behalf of Wenji Wu" <lustre-discuss-bounces at lists.lustre.org<mailto:lustre-discuss-bounces at lists.lustre.org> on behalf of wenji at fnal.gov<mailto:wenji at fnal.gov>> wrote:

Hello, everybody,

I understand that ext2/3/4 support FIEMAP to get file extent mapping.

Does Lustre supports similar feature like FIEMAP? Can Lustre client gets FIEMAP-like information on a Luster file system?

Thanks,

wenji