Linux considerations

About the read_ahead_kb kernel parameter

Starting with the MDEX Engine version 6.0, the MDEX Engine takes advantage of the readahead function.

Readahead is a technique employed by the Linux kernel that can improve file reading performance. If the kernel assumes that a particular file is being read sequentially, it attempts to read subsequent blocks from the file into memory before the application requests them. Setting the readahead can speed up the system's throughput, since the reading application does not have to wait as long for its subsequent requests, since they are served from cache in RAM, not from disk. However, in some cases the readahead setting generates unnecessary I/O operations and occupies memory pages which are needed for some other purpose. Therefore, tuning readahead for best performance is recommended.

You can tune readahead for optimum performance based on the settings recommended by Endeca.