safety of LVM snapshots on more volumes

[Jiří Hlinka]

Hello,
I want to be absolutely sure if I understand LVM snapshots for MySQL backup
well. As mentioned in that thread:
http://lists.mysql.com/replication/1241(" innodb replication"):

"FLUSH TABLES WITH READ LOCK should allow for a snapshot (LVM, ZFS) to be
used to copy all files -- as long as they are on the same filesystem."

...and according to other posts in that thread, it is safe to backup
innodb by taking LVM snapshot after TABLES WITH READ LOCK.

I'd like to know if it is safe with master-slave replication to:
1) take LVM snapshot when data files (innodb) are on one volume and
binary logs are on second volume.

According to the thread mentioned above (if i understand ti correctly)
this should be safe, because binlog will be lvm snapshoted (not in the
same
time because LVM cant make two atomic snapshots) and while in FLUSH
TABLES WITH READ LOCK ill note a exact binlog possition with SHOW
MASTER STATUS.

2) make LVM snapshot while innodb data files are stored on two partitions.

There sholud be problem, because data from two partitions arent in
consistent state because of non-atomic LVM snapshot of the two
partitions.

Thanks for help,
Jiri