We should use simple stripe in that case, which is why i have it defaulted to it now, someone was playing with twod-dist today and noticed that it defaults to having 2 groups, which causes errors when you run it on only a single server. I would much rather have the defaults allow the distribution to work on *any* setup, rather than just a n>1 servers setup.
Its not particularly useful, but I belive it is the right thing to do, maybe I'm wrong? (the original default settings are worthless for my applications so I have to change them anyhow) Kyle On Tue, Jul 1, 2008 at 4:04 PM, Sam Lang <[EMAIL PROTECTED]> wrote: > > Kyle, > > How is this patch useful for you guys? With a single server (and only one > stripe), it doesn't matter what the factor and num_groups are, does it? It > still behaves the same as simple-stripe in that case. With multiple servers > setting the factor and num_groups to 1 does make the 2d distribution act > like simple-stripe, but why not just use simple stripe in that case? > > -sam > > > On Jul 1, 2008, at 3:19 PM, Kyle Schochenmaier wrote: > >> Patch is against cvs head, and modifies the default num_groups to be 1 >> and the group_strip_factor = 1 so twod-stripe's defaults still work >> when you use it on a single-server, it will now by default behave the >> same as simple-stripe until the user modifies the num_groups and >> strip_factor xattrs. >> >> Also added a brief description of the definitions for the dist_params >> in twod-stripe. >> >> Tested fully functional on my servers. >> >> Kyle >> >> >> Index: src/io/description/dist-twod-stripe.c >> =================================================================== >> RCS file: /anoncvs/pvfs2/src/io/description/dist-twod-stripe.c,v >> retrieving revision 1.5 >> diff -r1.5 dist-twod-stripe.c >> 6a7,15 >>> >>> /* twod-stripe will take all of the servers in the filesystem and >>> * partition them into num_groups groups. Data will then be striped to >>> * each group before we move onto the next group. The strip_factor will >>> * determine how many chunks of strip_size are written to each server >>> * in each group before we transition to the next group. >>> * The striping on the group level is done round-robin in the same >>> * fashion as simple-stripe >>> */ >>> >> >> >> Index: include/pvfs2-dist-twod-stripe.h >> =================================================================== >> RCS file: /anoncvs/pvfs2/include/pvfs2-dist-twod-stripe.h,v >> retrieving revision 1.4 >> diff -r1.4 pvfs2-dist-twod-stripe.h >> 17c17 >> < #define PVFS_DIST_TWOD_STRIPE_DEFAULT_GROUPS 2 >> --- >>> >>> #define PVFS_DIST_TWOD_STRIPE_DEFAULT_GROUPS 1 >> >> 19c19 >> < #define PVFS_DIST_TWOD_STRIPE_DEFAULT_FACTOR 256 >> --- >>> >>> #define PVFS_DIST_TWOD_STRIPE_DEFAULT_FACTOR 1 >> >> >> - >> Kyle Schochenmaier >> <twod-dist.patch>_______________________________________________ >> Pvfs2-developers mailing list >> [email protected] >> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers > > -- Kyle Schochenmaier _______________________________________________ Pvfs2-developers mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
