Kurt, To clarify a bit further, the max_create_count is the maximum number of objects that the MDS might precreate in a batch on an OST if it has a high create rate. They are not necessarily _simultaneous_ creates.
In the recent IO-500 run, Cambridge sustained 1.78M creates/sec for 5 minutes (on 24 MDTs + 24*11 OSTs, mind you), so this is not a very high limit. On Jun 20, 2019, at 10:09, Degremont, Aurelien <degre...@amazon.com> wrote: > > Hello Kurt, > > max_create_count is a tunable per OST. It controls how many object > pre-creations could be done on each OST, by the MDT. If you set this to 0 for > one OST, no additional object will be allocated there and no new file will > have file stripes on it. > > With the appropriate hardware, Lustre can create much more than 20,000 files > simultaneously. > > Aurélien > > Kurt Strosahl <stros...@jlab.org> wrote on 2019-06-19 at 22:43: >> >> Good Afternoon, >> >> I'm in the process of testing a new lustre file system at 2.12, and in >> going through the documentation I saw that to stop writes from going to the >> system we now set the max_create_count to 0 on the mdt. >> >> I looked at that value on my system and the default seems to be 20000, am >> I correct in thinking that this is the maximum number of simultaneous >> creates that can happen on an OST? >> > Cheers, Andreas -- Andreas Dilger Principal Lustre Architect Whamcloud _______________________________________________ lustre-discuss mailing list lustre-discuss@lists.lustre.org http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
