Disable read-ahead caching for GFS2 Logical Volume

I have 10 node deployment which implement red hat clustering software - pacemaker/corosync to mount gfs2 and ensure high-availability. Nodes are actually mail servers and use gfs2 to store user's data in Maildir format. On each mail server i have the following gfs2 setup: root@mail ~# lsblk | grep gfs2 └─vg_1-lv_1 253:4 0 2T 0 lvm /mnt/gfs2_1 └─vg_2-lv_2 253:16 0 2T 0 lvm /mnt/gfs2_2 └─vg_3-lv_3 253:7 0 2T 0 lvm /mnt/gfs2_3 └─vg_4-lv_4 253:15 0 2T 0 lvm /mnt/gfs2_4 └─vg_5-lv_5 253:13 0 2T 0 lvm /mnt/gfs2_5 └─vg_6-lv_6 253:12 0 2T 0 lvm /mnt/gfs2_6 └─vg_7-lv_7 253:10 0 2T 0 lvm /mnt/gfs2_7 └─vg_8-lv_8 253:9 0 2T 0 lvm /mnt/gfs2_8 └─vg_9-lv_9 253:6 0 2T 0 lvm /mnt/gfs2_9 └─vg_10-lv_10 253:11 0 2T 0 lvm /mnt/gfs2_10 Now, i am not very pleased with my performance and my thinking is to remove read-ahead local cache on my gfs2 devices. Yes gfs2 uses local cache to serve clients more quickly, but as this information is not synced across all nodes, and we are not forcing single user to a single server, i am not sure this makes sense in terms of helping performance. Also, we are using dlm to force flushing outdated cached data across nodes. With all this being said, i am still not sure if this is the right move, and i am looking for an advice. 1) Is my thinking right - will this improve my fs performance or quite contrary? 2) Do you have any other advice that would improve my performance? Thank you in advance.