[lustre-discuss] [EXTERNAL] Re: Wrong striping when creating files inside a directory with explicit layout

[Mohr, Rick]

Santiago,

If you want to test the effects of increasing the number of osts, you can just specify the "-c <stripe_count>" option for your directory without having to specify a list of specific osts.  Lustre will then choose the set of osts for you.  This might be a good test to check if your output files end up getting created with the appropriate stripe count.

--Rick



On 12/7/25, 8:15 PM, "lustre-discuss on behalf of Santiago Freire - InCo via lustre-discuss" <lustre-discuss-bounces at lists.lustre.org> wrote:

Thank you Andreas for your response.
The application is a rather simple Python script that processes a large input file and writes many smaller output files in parallel based on a given criteria. I checked the code and it does not create files in a temporary directory nor renames them afterward, all output files are created directly in a single target directory. I also verified this with strace to make sure no unexpected rename operations were taking place.
All the OSTs are up and running. My current setup currently consists of one MDT and four OSTs. 
The reason I am trying to enforce a specific set of OSTs is that I am evaluating the performance benefits of increasing the number of OSTs for applications that consume and generate massive amounts of data. Because of this I need to experiment with different stripe configurations, using 1, 2, 3, or 4 OSTs. If you know a better way of achieving this purpose, I'd be grateful to hear your suggestions.
Thanks again for your help.
Santiago