From ccce8bbf109d3531df7ae5b6c65af04e9b48a757 Mon Sep 17 00:00:00 2001 From: Joseph Gmitter Date: Wed, 30 Oct 2019 10:51:03 -0400 Subject: [PATCH] LUDOC-442 dne: directory creation by space/inode This patch adds the feature documentation for the DNE work landed under LU-11213 and LU-12624 in Lustre 2.13. Signed-off-by: Joseph Gmitter Signed-off-by: Lai Siyao Change-Id: Ie76e0fae1fed92e30ebf1a4451895615d5a9c7d2 Reviewed-on: https://review.whamcloud.com/36615 Tested-by: jenkins --- LustreOperations.xml | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/LustreOperations.xml b/LustreOperations.xml index 55f4bc0..6f96ebf 100644 --- a/LustreOperations.xml +++ b/LustreOperations.xml @@ -518,6 +518,27 @@ client# lfs mkdir -c The striped directory feature is most useful for distributing single large directories (50k entries or more) across multiple MDTs, since it incurs more overhead than non-striped directories. +
+ Directory creation by space/inode usage + If the starting MDT is not specified when creating a new directory, + this directory and its stripes will be distributed on MDTs by space usage. + For example the following will create a directory and its stripes on MDTs + with balanced space usage: + lfs mkdir -c 2 <dir1> + Alternatively, if a default directory stripe is set on a directory, + the subsequent syscall mkdir under + <dir1> will have the same effect: + lfs setdirstripe -D -c 2 <dir1> + The policy is: + + If free inodes/blocks on all MDT are almost the same, + i.e. max_inodes_avail * 84% < min_inodes_avail and + max_blocks_avail * 84% < min_blocks_avail, then + choose MDT roundrobin. + Otherwise, create more subdirectories on MDTs with more + free inodes/blocks. + +
-- 1.8.3.1