From: Thierry Parmentelat <thierry.parmentelat@inria.fr>
Date: Fri, 8 Jul 2016 12:11:57 +0000 (+0200)
Subject: a few notes
X-Git-Tag: bootcd-5.4-1~2
X-Git-Url: http://git.onelab.eu/?p=bootcd.git;a=commitdiff_plain;h=a14f090f38c6130a6e8f82199a7e39bfd80bda2f

a few notes
---

diff --git a/fedoras.md b/fedoras.md
index 2cdf712..cab9096 100644
--- a/fedoras.md
+++ b/fedoras.md
@@ -1,4 +1,38 @@
-A few notes on the status wrt recent fedoras
+A few notes on the status wrt recent fedoras. 
+
+Written in July 2016, right after my early attempts with fedora24.
 
 # `/etc/resolv.conf`
 
+A change was observed starting with fedora22, and from then on we have seen recurring issues with nodes ending up with an empty `/etc/resolv.conf`
+
+## f22
+My understanding is that at the beginning this issue was only with statically defined IPs; in that case having `DNS1` and `DNS2` defined in a `ifcfg-`*ifname* was not enough, so there was a need to populate `/etc/resolv.conf` manually
+
+## f23
+It looks like with this release, the DNS servers defined by DHCP don't make it to `/etc/resolv.conf` either
+
+## Strategy
+
+### 5.4
+
+As of 5.4, the strategy here is to
+
+ * check if the file is missing or empty
+ * and if so, we populate it with
+   * nameservers coming from `DNS1` and `DNS2` if set, 
+   * and **in all cases** with `8.8.8.8`
+
+### 5.3
+
+Note that a 5.3 bootCD would **never** add `8.8.8.8`
+
+This could result in a node **not being able to resolve its boot server IP address**. Observed first hand on `onelab1.pl.sophia.fr` and its sibling `onelab2` with a f23 bootCD.
+
+# MAC address
+
+Also with fedora23, we noticed that we sometimes have to specify the MAC address in the interface details, so that the right interface gets picked.
+
+From a lot of reading I believe this has nothing to do with `biosdevname=0` which is something. It's just that on a multi-interfaces host, the bootCD environment may pick the wrong interface, so setting the MAC address allows to work around that issue.
+
+I cannot see how to improve this for the time being.
\ No newline at end of file
diff --git a/outline.md b/outline.md
index 31900e2..f3d8c89 100644
--- a/outline.md
+++ b/outline.md
@@ -1,3 +1,5 @@
+Just a few notes on how the whole boot sequence is organized
+
 # overall sequence (sysV init / systemd)
 
 * `pl_sysinit`