From e9f1c960c08ec8df66f05c45a1737ff74d69fe66 Mon Sep 17 00:00:00 2001 From: Blaine Gardner Date: Thu, 16 Dec 2021 16:13:43 -0700 Subject: [PATCH] docs: add jumbo frames note to common issues Resolves #9320 Signed-off-by: Blaine Gardner (cherry picked from commit 6c90d6687559adfda2e1e408cbc4fc3c1e7aa301) --- Documentation/ceph-common-issues.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/ceph-common-issues.md b/Documentation/ceph-common-issues.md index 2eb14de80164..a6a68b3c20bb 100644 --- a/Documentation/ceph-common-issues.md +++ b/Documentation/ceph-common-issues.md @@ -344,6 +344,10 @@ There are several common causes for the mons failing to form quorum: for cleaning the previous cluster. * A firewall may be blocking the ports required for the Ceph mons to form quorum. Ensure ports 6789 and 3300 are enabled. See the [Ceph networking guide](https://docs.ceph.com/en/latest/rados/configuration/network-config-ref/) for more details. +* There may be MTU mismatch between different networking components. Some networks may be more + susceptible to mismatch than others. If Kubernetes CNI or hosts enable jumbo frames (MTU 9000), + Ceph will use large packets to maximize network bandwidth. If other parts of the networking chain + don't support jumbo frames, this could result in lost or rejected packets unexpectedly. #### Operator fails to connect to the mon