[Lustre-devel] storing SOM epoch in EA

[Alex Zhuravlev <Alex.Zhuravlev@Sun.COM>]

Nikita Danilov wrote:
> One possible point here is that OSD has to do fid->ino translation
> anyway, and it makes sense to use the same index to store other
> information besides inode number. That is, we can use "object index" iam
> file to map fid into (ino, gen, ioepoch, LOV, ...) records, and this
> would not cause any additional seeks. The downside here is that object
> index is so heavily used, that making its records larger is going to
> increase the amount of IO significantly, so it only worth to place there
> things that we are absolutely sure will be needed for every inode.

well, we also need to update ioepoch when we update size/blocks.

thanks, Alex