[pve-devel] [PATCH docs v2 5/6] ceph: maintenance: revise and expand section "Replace OSDs"

[Alexander Zeidler]

Remove redundant information that is already described in section
“Destroy OSDs” and link to it.

Mention and link to the troubleshooting section, as replacing the OSD
may not fix the underyling problem.

Mention that the replacement disk should be of the same type and size
and comply with the recommendations.

Mention how to acknowledge warnings of crashed OSDs.

Signed-off-by: Alexander Zeidler <a.zeidler at proxmox.com>
---
v2
* no changes

 pveceph.adoc | 45 +++++++++++++--------------------------------
 1 file changed, 13 insertions(+), 32 deletions(-)

diff --git a/pveceph.adoc b/pveceph.adoc
index 81a6cc7..a471fb9 100644
--- a/pveceph.adoc
+++ b/pveceph.adoc
@@ -1035,43 +1035,24 @@ Ceph Maintenance
 Replace OSDs
 ~~~~~~~~~~~~
 
-One of the most common maintenance tasks in Ceph is to replace the 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. This rebalancing will start as
-soon as an OSD failure is detected or an OSD was actively stopped.
+With the following steps you can replace the disk of an OSD, which is
+one of the most common maintenance tasks in Ceph. If there is a
+problem with an OSD while its disk still seems to be healthy, read the
+xref:pve_ceph_mon_and_ts[troubleshooting] section first.
 
-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'.
+. If the disk failed, get a
+xref:pve_ceph_recommendation_disk[recommended] replacement disk of the
+same type and size.
 
-To replace a functioning disk from the GUI, go through the steps in
-xref:pve_ceph_osd_destroy[Destroy OSDs]. The only addition is to wait until
-the cluster shows 'HEALTH_OK' before stopping the OSD to destroy it.
+. xref:pve_ceph_osd_destroy[Destroy] the OSD in question.
 
-On the command line, use the following commands:
+. Detach the old disk from the server and attach the new one.
 
-----
-ceph osd out osd.<id>
-----
-
-You can check with the command below if the OSD can be safely removed.
-
-----
-ceph osd safe-to-destroy osd.<id>
-----
-
-Once the above check tells you that it is safe to remove the OSD, you can
-continue with the following commands:
-
-----
-systemctl stop ceph-osd@<id>.service
-pveceph osd destroy <id>
-----
+. xref:pve_ceph_osd_create[Create] the OSD again.
 
-Replace the old disk with the new one and use the same procedure as described
-in xref:pve_ceph_osd_create[Create OSDs].
+. After automatic rebalancing, the cluster status should switch back
+to `HEALTH_OK`. Any still listed crashes can be acknowledged by
+running, for example, `ceph crash archive-all`.
 
 Trim/Discard
 ~~~~~~~~~~~~
-- 
2.39.5