From d58f1849ffe534cba07049b0824b02aea8cb81c4 Mon Sep 17 00:00:00 2001 From: Andreas Dilger Date: Fri, 24 Feb 2012 02:04:22 -0700 Subject: [PATCH] LUDOC-11 ptlrpc: fix max_rpcs_in_flight_limit The maximum number of RPCs in flight per OSC is actually 256, not 32. Signed-off-by: Andreas Dilger Change-Id: Ie8e9ccbc56132d9112b03934dea004c0bd2faf9b --- LustreProc.xml | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/LustreProc.xml b/LustreProc.xml index 061fe0c..ece512a 100644 --- a/LustreProc.xml +++ b/LustreProc.xml @@ -475,7 +475,7 @@ blocksizefilesfree max_dirty_mb ost_server_uuid stats /proc/fs/lustre/osc/<object name>/max_pages_per_rpc This tunable is the maximum number of pages that will undergo I/O in a single RPC to the OST. The minimum is a single page and the maximum for this setting is platform dependent (256 for i386/x86_64, possibly less for ia64/PPC with larger PAGE_SIZE), though generally amounts to a total of 1 MB in the RPC. /proc/fs/lustre/osc/<object name>/max_rpcs_in_flight - This tunable is the maximum number of concurrent RPCs in flight from an OSC to its OST. If the OSC tries to initiate an RPC but finds that it already has the same number of RPCs outstanding, it will wait to issue further RPCs until some complete. The minimum setting is 1 and maximum setting is 32. If you are looking to improve small file I/O performance, increase the max_rpcs_in_flight value. + This tunable is the maximum number of concurrent RPCs in flight from an OSC to its OST. If the OSC tries to initiate an RPC but finds that it already has the same number of RPCs outstanding, it will wait to issue further RPCs until some complete. The minimum setting is 1 and maximum setting is 256. If you are looking to improve small file I/O performance, increase the max_rpcs_in_flight value. To maximize performance, the value for max_dirty_mb is recommended to be 4 * max_pages_per_rpc * max_rpcs_in_flight. The -- 1.8.3.1