From 86be506d85245885787acfdddd6b23f51031b1f0 Mon Sep 17 00:00:00 2001 From: Thomas Lamprecht Date: Thu, 5 Jul 2018 18:22:22 +0200 Subject: [PATCH] pveceph: reword RAID paragraph The "While ..." sentence seemed unfinished, reword paragraph Signed-off-by: Thomas Lamprecht --- pveceph.adoc | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/pveceph.adoc b/pveceph.adoc index bc8f4bf..8eca373 100644 --- a/pveceph.adoc +++ b/pveceph.adoc @@ -81,10 +81,13 @@ Check also the recommendations from http://docs.ceph.com/docs/luminous/start/hardware-recommendations/[Ceph's website]. .Avoid RAID -While RAID controller are build for storage virtualisation, to combine -independent disks to form one or more logical units. Their caching methods, -algorithms (RAID modes; incl. JBOD), disk or write/read optimisations are -targeted towards aforementioned logical units and not to Ceph. +As Ceph handles data object redundancy and multiple parallel writes to disks +(OSDs) on its own, using a RAID controller normally doesn’t improves +performance or availability. On the contrary, Ceph is designed to handle whole +disks on it's own, without any abstraction in between. RAID controller are not +designed for the Ceph use case and may complicate things and sometimes even +reduce performance, as their write and caching algorithms may interfere with +the ones from Ceph. WARNING: Avoid RAID controller, use host bus adapter (HBA) instead. -- 2.39.2