From c698995c2e9c52555ded1305b175abe89c895c93 Mon Sep 17 00:00:00 2001 From: John Spray Date: Mon, 20 Jun 2016 12:28:45 +0100 Subject: [PATCH] doc/cephfs: add advice about kernel versions Signed-off-by: John Spray --- doc/cephfs/early-adopters.rst | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/doc/cephfs/early-adopters.rst b/doc/cephfs/early-adopters.rst index 1047479f258..057d210b30b 100644 --- a/doc/cephfs/early-adopters.rst +++ b/doc/cephfs/early-adopters.rst @@ -41,6 +41,27 @@ When encountering bugs or performance issues, it is often instructive to try using the other client, in order to find out whether the bug was client-specific or not (and then to let the developers know). +Which kernel version? +--------------------- + +Because the kernel client is distributed as part of the linux kernel (not +as part of packaged ceph releases), +you will need to consider which kernel version to use on your client nodes. +Older kernels are known to include buggy ceph clients, and may not support +features that more recent Ceph clusters support. + +Remember that the "latest" kernel in a stable linux distribution is likely +to be years behind the latest upstream linux kernel where Ceph development +takes place (including bug fixes). + +As a rough guide, as of Ceph 10.x (Jewel), you should be using a least a +4.x kernel. If you absolutely have to use an older kernel, you should use +the fuse client instead of the kernel client. + +This advice does not apply if you are using a linux distribution that +includes CephFS support, as in this case the distributor will be responsible +for backporting fixes to their stable kernel: check with your vendor. + Reporting issues ================ -- 2.39.5