On Tue, Nov 13, 2012 at 01:56:59PM +0900, Tomoki Sekiyama wrote:
> Adds sample hook scripts for --fsfreeze-hook option of qemu-ga.
> - fsfreeze-hook : execute scripts in fsfreeze-hook.d/
> - fsfreeze-hook.d.sample/mysql-flush.sh : quiesce MySQL before snapshot
>
> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama...@hitachi.com>
Reviewed-by: Michael Roth <mdr...@linux.vnet.ibm.com>
> ---
> docs/qemu-guest-agent/fsfreeze-hook | 31 +++++++++++++
> .../fsfreeze-hook.d.sample/mysql-flush.sh | 47
> ++++++++++++++++++++
> 2 files changed, 78 insertions(+)
> create mode 100755 docs/qemu-guest-agent/fsfreeze-hook
> create mode 100755
> docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh
>
> diff --git a/docs/qemu-guest-agent/fsfreeze-hook
> b/docs/qemu-guest-agent/fsfreeze-hook
> new file mode 100755
> index 0000000..319f68c
> --- /dev/null
> +++ b/docs/qemu-guest-agent/fsfreeze-hook
> @@ -0,0 +1,31 @@
> +#!/bin/sh
> +
> +# This script is executed when a guest agent receives fsfreeze-freeze and
> +# fsfreeze-thaw command, if it is specified in --fsfreeze-hook (-F)
> +# option of qemu-ga or placed in default path (/etc/qemu/fsfreeze-hook).
> +# When the agent receives fsfreeze-freeze request, this script is issued with
> +# "freeze" argument before the filesystem is freezed. And for fsfreeze-thaw
> +# request, it is issued with "thaw" argument after filesystem is thawed.
> +
> +LOGFILE=/var/log/qga-fsfreeze-hook.log
> +FSFREEZE_D=$(dirname -- "$0")/fsfreeze-hook.d
> +
> +# Check whether file $1 is a backup or rpm-generated file and should be
> ignored
> +is_ignored_file() {
> + case "$1" in
> + *~ | *.bak | *.orig | *.rpmnew | *.rpmorig | *.rpmsave)
> + return 0 ;;
> + esac
> + return 1
> +}
> +
> +# Iterate executables in directory "fsfreeze-hook.d" with the specified args
> +[ ! -d "$FSFREEZE_D" ] && exit 1
> +for file in "$FSFREEZE_D"/* ; do
> + is_ignored_file "$file" && continue
> + [ -x "$file" ] || continue
> + echo "$(date): execute $file $@" >>$LOGFILE
> + "$file" "$@" >>$LOGFILE 2>&1
> + STATUS=$?
> + echo "$(date): $file finished with status=$STATUS" >>$LOGFILE
> +done
> diff --git a/docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh
> b/docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh
> new file mode 100755
> index 0000000..e6d7998
> --- /dev/null
> +++ b/docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh
> @@ -0,0 +1,47 @@
> +#!/bin/sh
> +
> +# Flush MySQL tables to the disk before the filesystem is freezed.
> +# At the same time, this keeps a read lock while the filesystem is freezed
> +# in order to avoid write accesses by the other clients.
> +
> +MYSQL="mysql -uroot" #"-prootpassword"
> +FIFO=/tmp/mysql-flush.fifo
> +
> +flush_and_wait() {
> + printf "FLUSH TABLES WITH READ LOCK \\G\n"
> + read < $FIFO
> + printf "UNLOCK TABLES \\G\n"
> +}
> +
> +case "$1" in
> + freeze)
> + mkfifo $FIFO || exit 1
> + flush_and_wait | $MYSQL &
> + # wait until every block is flushed
> + while [ "$(echo 'SHOW STATUS LIKE "Key_blocks_not_flushed"' |\
> + $MYSQL | tail -1 | cut -f 2)" -gt 0 ]; do
> + sleep 1
> + done
> + # for InnoDB, wait until every log is flushed
> + INNODB_STATUS=$(mktemp /tmp/mysql-flush.XXXXXX)
> + [ $? -ne 0 ] && exit 2
> + trap "rm -f $INNODB_STATUS" SIGINT
> + while :; do
> + printf "SHOW ENGINE INNODB STATUS \\G" | $MYSQL > $INNODB_STATUS
> + LOG_CURRENT=$(grep 'Log sequence number' $INNODB_STATUS |\
> + tr -s ' ' | cut -d' ' -f4)
> + LOG_FLUSHED=$(grep 'Log flushed up to' $INNODB_STATUS |\
> + tr -s ' ' | cut -d' ' -f5)
> + [ "$LOG_CURRENT" = "$LOG_FLUSHED" ] && break
> + sleep 1
> + done
> + rm -f $INNODB_STATUS
> + ;;
> +
> + thaw)
> + [ ! -p $FIFO ] && exit 1
> + echo > $FIFO
> + rm -f $FIFO
> + ;;
> +esac
> +
>
