That is correct. The behavior can be different if you open in append mode versus just opening and then appending. For example, if you have a directory with default stripe count of 3, then running "touch foo; echo 'a' >> foo" will create a file with stripe count 3. But if the file is create by just running " echo 'a' >> foo", then the file will be created with stripe count 1 by default. The default striping for O_APPEND files can be controlled with the append_stripe_count parameter. See https://doc.lustre.org/lustre_manual.xhtml#file_striping.considerations for more details.
(Santiago: That could explain why you were getting files with stripe count 1. I missed the info about appending to files when I first read your message.) --Rick On 12/8/25, 10:36 AM, "lustre-discuss on behalf of Vicker, Darby J. (JSC-EG311)[AMENTUM TECHNOLOGY, INC] via lustre-discuss" <[email protected] <mailto:[email protected]> on behalf of [email protected] <mailto:[email protected]>> wrote: > The application creates files with standard POSIX I/O (open() followed by > appends and writes), nothing exotic or MPI-IO-related. If I remember correctly, files opened in append mode are treated differently by the lustre client and don’t necessarily obey the stripping set on its parent directory. I don’t recall the details at the moment but perhaps that is contributing to the behavior Santiago is experiencing? _______________________________________________ lustre-discuss mailing list [email protected] http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
