I'm running the following command:

[root@somehost ~]# ec2-consistent-snapshot --aws-credentials-file '/some/dir/file' --mysql --mysql-socket '/var/run/mysqld/mysql.sock' --mysql-username 'backup' --mysql-password 'password' --freeze-filesystem '/dev/xvda1' vol-xxxxxx

It returns this error:

xfs_freeze: cannot freeze filesystem at /dev/xvda1: Operation not supported
ec2-consistent-snapshot: ERROR: xfs_freeze -f /dev/xvda1: failed(256)
snap-eeb66393
xfs_freeze: cannot unfreeze filesystem mounted at /dev/xvda1: Invalid argument
ec2-consistent-snapshot: ERROR: xfs_freeze -u /dev/xvda1: failed(256)

This is being run on Debian Squeeze with the ext4 Linux filesystem.

Can anyone explain this error to me, or what might be its cause? When googling, I found information about it needing to be executed with sudo, but I'm performing the entire operation as root. I also found some posts about trying to run it after a CentOS upgrade using yum, but the situation appeared dissimilar. It's difficult to find things referring to this situation exactly. xfs_freeze is available for use on the filesystem. Is it possible that the filesystem, despite being ext4, somehow doesn't support freezing? Sorry if I've missed some bit of StackExchange etiquette with this post -- it's my first venture here!