I am pretty new to Lustre and trying to understand a few things wrt to the File Read/Write operations.

1. When the client wants to read a file, it obtains the EA layout information for that file from the MDT and then accesses the file directly from OST(s).

2. When the client wants to write a file, it contacts the MDT and MDT would provide the list of OSTs on which the file could be striped across. (MDT gives OSTs based on the available free space in OSTs - round robin or weighted as given in manual).

--> Once the client completes the write operation, would the client inform the MDS about the completion and so release the locks on file metadata or the OSS/OST would communicate this information to the MDS/MDT ??

P.S: I still haven't played with the installation part to capture and check the flow of messages to confirm this. Any inputs that you have based on your experiences would be valuable. Thanks!!

Regards,
Akhilesh.