From 6bf6848b525f08e60997d81e98e7498bd86bdc38 Mon Sep 17 00:00:00 2001 From: Sridhar Seshasayee Date: Thu, 7 Apr 2022 23:14:29 +0530 Subject: [PATCH] doc/releases/quincy: Update 'mclock_scheduler' release note. Signed-off-by: Sridhar Seshasayee --- doc/releases/quincy.rst | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/doc/releases/quincy.rst b/doc/releases/quincy.rst index ffb599e45b6..cfb7f8b21d9 100644 --- a/doc/releases/quincy.rst +++ b/doc/releases/quincy.rst @@ -83,10 +83,20 @@ RADOS are no existing internal users of this object class, it is not packaged anymore. -* OSD: Ceph now uses `mclock_scheduler` for bluestore OSDs as its default +* OSD: Ceph now uses `mclock_scheduler` for BlueStore OSDs as its default `osd_op_queue` to provide QoS. The 'mclock_scheduler' is not supported - for filestore OSDs. Therefore, the default 'osd_op_queue' is set to 'wpq' - for filestore OSDs and is enforced even if the user attempts to change it. + for Filestore OSDs. Therefore, the default 'osd_op_queue' is set to `wpq` + for Filestore OSDs and is enforced even if the user attempts to change it. + For more details on configuring mclock see, + + https://docs.ceph.com/en/latest/rados/configuration/mclock-config-ref/ + + An outstanding issue exists during runtime where the mclock config options + related to reservation, weight and limit cannot be modified after switching + to the `custom` mclock profile using the `ceph config set ...` command. + This is tracked by: https://tracker.ceph.com/issues/55153. Until the issue + is fixed, users are advised to avoid using the 'custom' profile or use the + workaround mentioned in the tracker. * MGR: The pg_autoscaler has a new 'scale-down' profile, which provides more performance from the start for new pools. However, the module still uses -- 2.39.5