[LUDOC-417] modify Manual 37.4.2.1, Tuning File Read Ahead, to include description of “max_read_ahead_per_file_mb”

Tue, 25 Sep 2018 16:09:13 +0000

Lustre Manual section 37.4.2.1, Tuning File Read Ahead, describes both “max_read_ahead_mb” and “max_read_ahead_whole_mb” but there is no mention of “max_read_ahead_per_file_mb.”

It would be useful first to add a description of the effects of setting max_read_ahead_per_file_mb and then also to include its interactions with the other already-mentioned parameters. For example, it seems that the order of setting these parameters makes a difference in whether the values are accepted or rejected as "out of range."

Whamcloud Community JIRA

[LUDOC-417] modify Manual 37.4.2.1, Tuning File Read Ahead, to include description of “max_read_ahead_per_file_mb”