[Pvfs2-users] PVFS2 directory attributes

[Phil Carns]

Hi Xuechen,

I believe that this is possible with the varstrip distribution in PVFS. 
  Here is some further information:

http://www.pvfs.org/fisheye/browse/PVFS/doc/pvfs2-tuning.tex?r=1.1.22.1#l328

For example, I think on directory A you would set something like:

   setfattr -n user.pvfs2.dist_name -v varstrip_dist A
   setfattr -n user.pvfs2.dist_params -v "strips:0:64K;1:64K" A

And this for B:

   setfattr -n user.pvfs2.dist_name -v varstrip_dist B
   setfattr -n user.pvfs2.dist_params -v "strips:2:64K;3:64K" B

That should automatically set the number of datafiles to 2 based on the 
distribution parameters, but it is possible that some previous releases 
didn't do that.  If you have trouble use these commands to make it explicit:

   setfattr -n user.pvfs2.num_dfiles -v "2" A
   setfattr -n user.pvfs2.num_dfiles -v "2" B

A few other misc. pointers:

- this only affects new files in any given directory and does not change 
existing files

- make sure to test the results by using "pvfs2-viewdist -f <filename>" 
to see how new files are distributed

-Phil

Xuechen Zhang wrote:
> There is a question about setting PVFS2 directory attributes. I have 
> four I/O servers (0-3). I want to locate file A in directory A on server 
> 0&1 and file B in directory B on server 2&3 by settting stripe 
> distribution for the two directory. Can I implement this kind of 
> distribution in PVFS2? If not, any suggestion for that? Thanks.
> 
> Xuechen
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Pvfs2-users mailing list
> Pvfs2-users at beowulf-underground.org
> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users