From: Thomas Lamprecht Date: Wed, 6 Nov 2019 17:50:11 +0000 (+0100) Subject: ceph: add a bit to OSD replacement X-Git-Url: https://git.proxmox.com/?p=pve-docs.git;a=commitdiff_plain;h=af6f59f49f55a42b15cc52c49497baf80aed5c0b ceph: add a bit to OSD replacement Signed-off-by: Thomas Lamprecht --- diff --git a/pveceph.adoc b/pveceph.adoc index 825bd8a..d01ae46 100644 --- a/pveceph.adoc +++ b/pveceph.adoc @@ -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 @@ -750,9 +758,6 @@ pveceph osd destroy 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) ~~~~~~~~~~~~~~~~~~~~ It is a good measure to run 'fstrim' (discard) regularly on VMs or containers.