From 612b02862682c4fa9c965317e08d9c3146fe6fd9 Mon Sep 17 00:00:00 2001 From: Dan van der Ster Date: Thu, 12 Nov 2020 17:14:37 +0100 Subject: [PATCH] common/options: bluefs_buffered_io=true by default Enable bluefs_buffered_io again because it makes a huge user-visible improvement in metadata intensive scenarios, such as but not limited to PG deletion. In our environment, deleting PGs from 4 hybrid OSDs (sharing one SATA SSD block.db) saturates the block.db at 350MB/s reads and causes slow reqs and flapping on the OSDs. Those OSDs have 3GB osd_target_memory. Enabling bluefs_buffered_io drops the SSD IO down to <1MBps and the OSDs are performant again. (The underlying PG deletion inefficiency is being solved separately, but the page cache is so much more effective than the bluestore cache in this scenario). Lastly, remove the comment about swap. We should separately advise operators to disable swap on OSD machines, as it is much better in our experience to OOM and restart than to chug along swapping. Signed-off-by: Dan van der Ster Related-to: https://tracker.ceph.com/issues/45765 Related-to: https://tracker.ceph.com/issues/47044 (cherry picked from commit 5ec8e8e63d409860c35e24a192090ac2b70af8f6) --- src/common/options.cc | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/common/options.cc b/src/common/options.cc index 6f33372873aef..4dcdaf0783b8f 100644 --- a/src/common/options.cc +++ b/src/common/options.cc @@ -4203,9 +4203,9 @@ std::vector