[Voyage-linux] aufs: Sync to flash with our reboot ?

[Mike O'Connor]

Hi Guido

I'm trying out this script, I seem to have a problem, the /var/log
directory is not being overlaided with aufs.

voyage:/tmp/voyage-0.6.1/etc/rc1.d# cat /proc/mounts
rootfs / rootfs rw 0 0
none /sys sysfs rw,nosuid,nodev,noexec 0 0
none /proc proc rw,nosuid,nodev,noexec 0 0
udev /dev tmpfs rw,size=10240k,mode=755 0 0
/dev/disk/by-label/ROOT_FS / ext2 rw,noatime,errors=continue 0 0
tmpfs /lib/init/rw tmpfs rw,nosuid,mode=755 0 0
varrun /var/run tmpfs rw,nosuid,mode=755 0 0
varlock /var/lock tmpfs rw,nosuid,nodev,noexec 0 0
usbfs /proc/bus/usb usbfs rw,nosuid,nodev,noexec 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
devpts /dev/pts devpts rw,nosuid,noexec,gid=5,mode=620 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev 0 0

Which means the remount,ro during the boot process fails.

I see during the boot process it doing the voyage-sync start, no errors
are printed to the screen.

I think the issue is that syslogd has been restarted before the mounting
of aufs.

One thing to note is that I have done a apt-get upgrade before starting
the proccess of getting the new voyage-sync

Mike



Guido De Rosa wrote:
> 2009/3/30 Kim-man 'Punky' TSE <punkytse at punknix.com>:
>
>   
>> I would try I could have some update on it later this week. �After I tested
>> Guido's update and some of my additions.
>>     
>
> Hi! Please always consider the last update:
>
> http://bitbucket.org/gderosa/net-appliances/src/tip/voyage/etc/init.d/voyage-sync
>
> Specifically, since rev9, some extra check has been added:
>
> 			# verify that $SYNC_DIR is actually mounted as a
> 			# $UNIONFS; otherwise, avoid dangerous over-writings
> 			# of $SYNCFS_ROOT/$SYNC_DIR
> 			if (mount | grep $SYNC_DIR | grep "type $UNIONFS" > /dev/null) ; then
> 				echo -n "  Sync'ing $SYNC_DIR to $SYNCFS_ROOT$SYNC_DIR ... "
> 				rsync $RSYNC_OPTS $SYNC_DIR $SYNCFS_ROOT/`dirname $SYNC_DIR`
> 				log_action_end_msg $?
> 			fi
>
> Think about the following scenario:you've been using AUFS/UNIONFS for
> a while and recently you have upgraded the kernel, but forgot to add
> aufs support; you also have added to VOYAGE_SYNC_DIRS some directories
> with important data; in this scenario, after the first reboot,
> mounting of $SYNC_DIR fails, and you get stuck with old $SYNC_DIR
> contained in your root partition. After another reboot, new data in
> $SYNCFS_ROOT are overwritten by older ones which is definitely not
> what you want. That's why an extra check is necessary.
>
> So, just for the first time, when you just added a new directory to
> VOYAGE_SYNC_DIR, you will have to manually copy it to  $SYNCFS_ROOT/ .
>
> (Maybe an helper function could be added to
> /usr/local/sbin/voyage-sync to do this syncing-without-checking
> automatically, but definitely not in /etc/init.d )
>
>