bump version to 6.1-4

[pve-docs.git] / pveceph.adoc

diff --git a/pveceph.adoc b/pveceph.adoc
index 825bd8a83363c6084f0225510eb230ba10175455..8b86d62f596767f35ca8b8164cfcda5aa4bc8f11 100644 (file)
--- a/pveceph.adoc
+++ b/pveceph.adoc
@@ -18,8 +18,8 @@ DESCRIPTION
 -----------
 endif::manvolnum[]
 ifndef::manvolnum[]
-Manage Ceph Services on Proxmox VE Nodes
-========================================
+Deploy Hyper-Converged Ceph Cluster
+===================================
 :pve-toplevel:
 endif::manvolnum[]
 
@@ -286,7 +286,7 @@ monitor the cluster. Since the Ceph luminous release at least one ceph-mgr
 footnote:[Ceph Manager https://docs.ceph.com/docs/{ceph_codename}/mgr/] daemon is
 required.
 
-[i[pveceph_create_mgr]]
+[[pveceph_create_mgr]]
 Create Manager
 ~~~~~~~~~~~~~~
 
@@ -719,12 +719,20 @@ pveceph pool destroy NAME
 
 Ceph maintenance
 ----------------
+
 Replace OSDs
 ~~~~~~~~~~~~
+
 One of the common maintenance tasks in Ceph is to replace a disk of an OSD. If
 a disk is already in a failed state, then you can go ahead and run through the
 steps in xref:pve_ceph_osd_destroy[Destroy OSDs]. Ceph will recreate those
-copies on the remaining OSDs if possible.
+copies on the remaining OSDs if possible. This rebalancing will start as soon
+as an OSD failure is detected or an OSD was actively stopped.
+
+NOTE: With the default size/min_size (3/2) of a pool, recovery only starts when
+`size + 1` nodes are available. The reason for this is that the Ceph object
+balancer xref:pve_ceph_device_classes[CRUSH] defaults to a full node as
+`failure domain'.
 
 To replace a still functioning disk, on the GUI go through the steps in
 xref:pve_ceph_osd_destroy[Destroy OSDs]. The only addition is to wait until
@@ -750,24 +758,23 @@ pveceph osd destroy <id>
 Replace the old disk with the new one and use the same procedure as described
 in xref:pve_ceph_osd_create[Create OSDs].
 
-NOTE: With the default size/min_size (3/2) of a pool, recovery only starts when
-`size + 1` nodes are available.
-
-Run fstrim (discard)
-~~~~~~~~~~~~~~~~~~~~
+Trim/Discard
+~~~~~~~~~~~~
 It is a good measure to run 'fstrim' (discard) regularly on VMs or containers.
 This releases data blocks that the filesystem isn’t using anymore. It reduces
-data usage and the resource load.
+data usage and resource load. Most modern operating systems issue such discard
+commands to their disks regularly. You only need to ensure that the Virtual
+Machines enable the xref:qm_hard_disk_discard[disk discard option].
 
 [[pveceph_scrub]]
 Scrub & Deep Scrub
 ~~~~~~~~~~~~~~~~~~
 Ceph ensures data integrity by 'scrubbing' placement groups. Ceph checks every
 object in a PG for its health. There are two forms of Scrubbing, daily
-(metadata compare) and weekly. The weekly reads the objects and uses checksums
-to ensure data integrity. If a running scrub interferes with business needs,
-you can adjust the time when scrubs footnote:[Ceph scrubbing
-https://docs.ceph.com/docs/{ceph_codename}/rados/configuration/osd-config-ref/#scrubbing]
+cheap metadata checks and weekly deep data checks. The weekly deep scrub reads
+the objects and uses checksums to ensure data integrity. If a running scrub
+interferes with business (performance) needs, you can adjust the time when
+scrubs footnote:[Ceph scrubbing https://docs.ceph.com/docs/{ceph_codename}/rados/configuration/osd-config-ref/#scrubbing]
 are executed.