[lxc-devel] [PATCH] add zfs support to lxc-create and lxc-destroy
Serge Hallyn
serge.hallyn at ubuntu.com
Thu Apr 25 20:18:25 UTC 2013
This is based on patch from Papp Tamas (thanks). It also does some
reorganizing of lxc-create to commonize some of the backingstore handling.
I played with it using:
sudo lvcreate -L 100G -n zfs vg0
sudo zpool create lxc /dev/vg0/zfs
sudo lxc-create -B zfs --zfsroot lxc -t ubuntu -n dir2
or you could
qemu-img create zfs.img 100G
sudo qemu-nbd -c /dev/nbd0 zfs.img
sudo zpool create lxc /dev/nbd0
sudo lxc-create -B zfs --zfsroot lxc -t ubuntu -n dir2
I'll write the bdev.c handler and hook up lxc-clone next.
This also fixses a bug in the sed expression to extract the rootfs from
container config, which prepended an extra '/' to the rootdev. (That
caused the zfs list entry not to match at destroy)
Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
Cc: Papp Tamas <tompos at martos.bme.hu>
---
src/lxc/lxc-create.in | 167 ++++++++++++++++++++++++++++++++----------------
src/lxc/lxc-destroy.in | 13 +++-
2 files changed, 124 insertions(+), 56 deletions(-)
diff --git a/src/lxc/lxc-create.in b/src/lxc/lxc-create.in
index fbb566f..3367a89 100644
--- a/src/lxc/lxc-create.in
+++ b/src/lxc/lxc-create.in
@@ -22,6 +22,59 @@
. @DATADIR@/lxc/lxc.functions
+verify_btrfs() {
+ if which btrfs >/dev/null 2>&1 && \
+ btrfs filesystem df "$lxc_path/" >/dev/null 2>&1; then
+ echo "btrfs"
+ else
+ echo "no"
+ fi
+}
+
+verify_zfs() {
+ if which zfs >/dev/null 2>&1 && zfs get all "$zfs_root" >/dev/null 2>&1; then
+ echo zfs
+ else
+ echo no
+ fi
+}
+
+verify_lvm() {
+ which vgscan > /dev/null 2>&1
+ if [ $? -ne 0 ]; then
+ echo "vgscan not found (is lvm2 installed?)" >&2
+ echo no
+ return
+ fi
+
+ grep -q "\<$fstype\>" /proc/filesystems
+ if [ $? -ne 0 ]; then
+ echo "$fstype is not listed in /proc/filesystems" >&2
+ echo no
+ return
+ fi
+
+ vgscan | grep -q "Found volume group \"$vgname\""
+ if [ $? -ne 0 ]; then
+ echo "could not find volume group \"$vgname\"" >&2
+ echo no
+ return
+ fi
+
+ echo lvm
+}
+
+# if no backingstore is specified, auto-detect if $lxc_path is btrfs or zfs
+detect_backingstore() {
+ if [ `verify_btrfs` = "btrfs" ]; then
+ echo btrfs
+ elif [ `verify_zfs` = "zfs" ]; then
+ echo zfs
+ else
+ echo none
+ fi
+}
+
usage() {
echo "usage: $(basename $0) -n NAME [-f CONFIG_FILE] [-t TEMPLATE] [FS_OPTIONS] --" >&2
echo " [-P lxcpath] [TEMPLATE_OPTIONS]" >&2
@@ -32,6 +85,7 @@ usage() {
echo " -B lvm [--lvname LV_NAME] [--vgname VG_NAME] [--fstype FS_TYPE]" >&2
echo " [--fssize FS_SIZE]" >&2
echo " -B btrfs" >&2
+ echo " -B zfs [--zfsroot PATH]" >&2
}
help() {
@@ -51,6 +105,7 @@ help() {
echo " --vgname VG_NAME specify the LVM volume group name (default: lxc)" >&2
echo " --fstype FS_TYPE specify the filesystem type (default: ext4)" >&2
echo " --fssize FS_SIZE specify the filesystem size (default: 500M)" >&2
+ echo " --zfsroot PATH specify the zfs path for lxcpath (default: tank/lxc)" >&2
echo >&2
if [ -z "$lxc_template" ]; then
echo "To see template-specific options, specify a template. For example:" >&2
@@ -140,6 +195,11 @@ while [ $# -gt 0 ]; do
fssize=$1
shift
;;
+ --zfsroot)
+ optarg_check $opt "$1"
+ zfs_root=$1
+ shift
+ ;;
--)
break;;
-?)
@@ -187,6 +247,10 @@ if [ -z "$lvname" ]; then
lvname="$lxc_name"
fi
+if [ -z "$zfs_root" ]; then
+ zfs_root="tank/lxc"
+fi
+
if [ "$(id -u)" != "0" ]; then
echo "$(basename $0): must be run as root" >&2
exit 1
@@ -196,10 +260,39 @@ if [ -n "$custom_rootfs" ] && [ "$backingstore" != "dir" ]; then
echo "--dir is only valid with -B dir"
fi
+# detect / verify backing store
case "$backingstore" in
- dir|lvm|none|btrfs|_unset) :;;
+ btrfs)
+ if [ `verify_btrfs` != 'btrfs' ]; then
+ echo "missing 'btrfs' command or $lxc_path is not btrfs" >&2
+ exit 1
+ fi
+ ;;
+ zfs)
+ if [ `verify_zfs` != 'zfs' ]; then
+ echo "missing 'zfs' command or $zfs_root is not zfs" >&2
+ exit 1
+ fi
+ ;;
+ lvm)
+ if [ `verify_lvm` != 'lvm' ]; then
+ echo "system is missing 'lvm' support, or VG does not exist." >&2
+ exit 1
+ fi
+ rootdev=/dev/$vgname/$lvname
+ lvdisplay $rootdev > /dev/null 2>&1
+ if [ $? -eq 0 ]; then
+ echo "LV $rootdev already exists" >&2
+ exit 1
+ fi
+ ;;
+ _unset)
+ backingstore=`detect_backingstore`
+ ;;
+ dir|lvm|none)
+ :;;
*)
- echo "$(basename $0): '$backingstore' is not known (try 'none', 'dir', 'lvm', 'btrfs')" >&2
+ echo "$(basename $0): '$backingstore' is not known (try 'none', 'dir', 'lvm', 'btrfs', 'zfs')" >&2
usage
exit 1
;;
@@ -212,61 +305,14 @@ fi
rootfs="$lxc_path/$lxc_name/rootfs"
-if [ "$backingstore" = "_unset" ] || [ "$backingstore" = "btrfs" ]; then
-# if no backing store was given, then see if btrfs would work
- if which btrfs >/dev/null 2>&1 && \
- btrfs filesystem df "$lxc_path/" >/dev/null 2>&1; then
- backingstore="btrfs"
- else
- if [ "$backingstore" = "btrfs" ]; then
- echo "$(basename $0): missing 'btrfs' command or $lxc_path is not btrfs" >&2
- exit 1;
- fi
- backingstore="none"
- fi
-fi
-
-if [ "$backingstore" = "lvm" ]; then
- which vgscan > /dev/null 2>&1
- if [ $? -ne 0 ]; then
- echo "$(basename $0): vgscan not found (is lvm2 installed?)" >&2
- exit 1
- fi
-
- grep -q "\<$fstype\>" /proc/filesystems
- if [ $? -ne 0 ]; then
- echo "$(basename $0): $fstype is not listed in /proc/filesystems" >&2
- exit 1
- fi
-
- vgscan | grep -q "Found volume group \"$vgname\""
- if [ $? -ne 0 ]; then
- echo "$(basename $0): could not find volume group \"$vgname\"" >&2
- exit 1
- fi
-
- rootdev=/dev/$vgname/$lvname
- lvdisplay $rootdev > /dev/null 2>&1
- if [ $? -eq 0 ]; then
- echo "$(basename $0): backing store already exists: $rootdev" >&2
- echo "please delete it (using \"lvremove $rootdev\") and try again" >&2
- exit 1
- fi
-
-elif [ "$backingstore" = "btrfs" ]; then
- mkdir "$lxc_path/$lxc_name"
- if ! out=$(btrfs subvolume create "$rootfs" 2>&1); then
- echo "$(basename $0): failed to create subvolume in $rootfs: $out" >&2
- exit 1;
- fi
-fi
-
cleanup() {
if [ "$backingstore" = "lvm" ]; then
- umount $rootfs
- lvremove -f $rootdev
+ umount -l $rootfs || true
+ lvremove -f $rootdev || true
elif [ "$backingstore" = "btrfs" ]; then
- btrfs subvolume delete "$rootfs"
+ btrfs subvolume delete "$rootfs" || true
+ elif [ "$backingstore" = "zfs" ]; then
+ zfs destroy "$zfs_root/$lxc_name" || true
fi
${bindir}/lxc-destroy -n $lxc_name
@@ -276,7 +322,18 @@ cleanup() {
trap cleanup HUP INT TERM
-mkdir -p $lxc_path/$lxc_name
+# set up container dir per backing store
+if [ "$backingstore" = "zfs" ]; then
+ zfs create -omountpoint=$lxc_path/$lxc_name/rootfs "$zfs_root/$lxc_name"
+elif [ "$backingstore" = "btrfs" ]; then
+ mkdir "$lxc_path/$lxc_name"
+ if ! out=$(btrfs subvolume create "$rootfs" 2>&1); then
+ echo "$(basename $0): failed to create subvolume in $rootfs: $out" >&2
+ exit 1;
+ fi
+else
+ mkdir -p $lxc_path/$lxc_name
+fi
if [ -z "$lxc_config" ]; then
lxc_config="@SYSCONFDIR@/lxc/default.conf"
diff --git a/src/lxc/lxc-destroy.in b/src/lxc/lxc-destroy.in
index 6514085..fc164c2 100644
--- a/src/lxc/lxc-destroy.in
+++ b/src/lxc/lxc-destroy.in
@@ -46,6 +46,15 @@ usage_err() {
exit 1
}
+verify_zfs() {
+ path=$1
+ if which zfs >/dev/null 2>&1 && zfs list | grep -q $path; then
+ echo zfs
+ else
+ echo no
+ fi
+}
+
optarg_check() {
if [ -z "$2" ]; then
usage_err "option '$1' requires an argument"
@@ -123,7 +132,7 @@ fi
# Deduce the type of rootfs
# If LVM partition, destroy it. For btrfs, we delete the subvolue. If anything
# else, ignore it. We'll support deletion of others later.
-rootdev=`grep lxc.rootfs $lxc_path/$lxc_name/config 2>/dev/null | sed -e 's/^[^/]*/\//'`
+rootdev=`grep lxc.rootfs $lxc_path/$lxc_name/config 2>/dev/null | sed -e 's/^[^/]*//'`
if [ -n "$rootdev" ]; then
if [ -b "$rootdev" -o -h "$rootdev" ]; then
lvdisplay $rootdev > /dev/null 2>&1
@@ -131,6 +140,8 @@ if [ -n "$rootdev" ]; then
echo "removing backing store: $rootdev"
lvremove -f $rootdev
fi
+ elif [ `verify_zfs $rootdev` = "zfs" ]; then
+ zfs destroy $(zfs list | grep $rootdev | awk '{ print $1 }')
elif [ -h "$rootdev" -o -d "$rootdev" ]; then
if which btrfs >/dev/null 2>&1 &&
btrfs subvolume list "$rootdev" >/dev/null 2>&1; then
--
1.7.9.5
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