From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Fri, 30 Sep 2011 17:33:26 +0000 (-0700)
Subject: Synchronize initramfs and system hostid
X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=commitdiff_plain;h=e8753fb4f03aaa371028aaec145449f2610229cf;p=zfs.git

Synchronize initramfs and system hostid

Relying on an /etc/hostid file which is installed in the system
image breaks diskless systems which share an image.  Certain
cluster infrastructure such as MPI relies on all nodes having
a unique hostid.  However, we still must be careful to ensure
the hostid is syncronized between the initramfs and system
images when using zfs root filesystems.

To accompish this the automatically created /etc/hostid file has
been removed from the spl rpm packaging.  The /etc/hostid file
is now dynamically created for your initramfs as part of the
dracut install process.  This avoids the need to install it in
the actual system images.

This change also resolves the spl_hostid parameter handling
for dracut.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #398
Closes #399

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
---

diff --git a/dracut/90zfs/module-setup.sh.in b/dracut/90zfs/module-setup.sh.in
index 33f78e5..c01915e 100755
--- a/dracut/90zfs/module-setup.sh.in
+++ b/dracut/90zfs/module-setup.sh.in
@@ -33,7 +33,6 @@ install() {
 	inst_rules @udevruledir@/60-zvol.rules
 	inst @sysconfdir@/zfs/zdev.conf
 	inst @sysconfdir@/zfs/zpool.cache
-	inst @sysconfdir@/hostid
 	dracut_install @sbindir@/zfs
 	dracut_install @sbindir@/zpool
 	dracut_install @bindir@/zpool_layout
@@ -43,4 +42,14 @@ install() {
 	dracut_install hostid
 	inst_hook cmdline 95 "$moddir/parse-zfs.sh"
 	inst_hook mount 98 "$moddir/mount-zfs.sh"
+
+	# Synchronize initramfs and system hostid
+	TMP=`mktemp`
+	AA=`hostid | cut -b 1,2`
+	BB=`hostid | cut -b 3,4`
+	CC=`hostid | cut -b 5,6`
+	DD=`hostid | cut -b 7,8`
+	printf "\x$DD\x$CC\x$BB\x$AA" >$TMP
+	inst_simple "$TMP" /etc/hostid
+	rm "$TMP"
 }
diff --git a/dracut/90zfs/parse-zfs.sh.in b/dracut/90zfs/parse-zfs.sh.in
index 13697b9..571d263 100755
--- a/dracut/90zfs/parse-zfs.sh.in
+++ b/dracut/90zfs/parse-zfs.sh.in
@@ -6,9 +6,13 @@
 spl_hostid=`getarg spl_hostid=`
 if [ "${spl_hostid}" != "" ] ; then
 	info "ZFS: Using hostid from command line: ${spl_hostid}"
-	echo "${spl_hostid}" > /etc/hostid
+	AA=`echo ${spl_hostid} | cut -b 1,2`
+	BB=`echo ${spl_hostid} | cut -b 3,4`
+	CC=`echo ${spl_hostid} | cut -b 5,6`
+	DD=`echo ${spl_hostid} | cut -b 7,8`
+	printf "\x$DD\x$CC\x$BB\x$AA" >/etc/hostid
 elif [ -f /etc/hostid ] ; then
-	info "ZFS: Using hostid from /etc/hostid: `cat /etc/hostid`"
+	info "ZFS: Using hostid from /etc/hostid: `hostid`"
 else
 	warn "ZFS: No hostid found on kernel command line or /etc/hostid.  "
 	warn "ZFS: Pools may not import correctly."