Time expectations on log scan?

The problem:
Using innobackupex, the files copy over quickly (10 minutes) to a remote server and then the log scanning starts.
The log scanning was taking over 5 hours before I cancelled the backup.
I know the documentation says it can take a long time on a large database, but that is all relevant.

Background:
I just started testing xtrabackup. In the past I was just using mysqldump
I was in the habit of performing 4 snapshots a day on 50GB MySQL databases. This is not obtainable in this scenario.
I was looking for a number in the 1 hour range for a backup. Ultimately I will need to restore this to the Master server.

My questions:
Is it normal to wait 5+ hours for the log scanning?
Is there any benchmarking data with different size databases?
Is there a better strategy for this process?

At this point, I don’t live and breath MySQL on a daily basis so any guidance would be helpful.

Thank you
Derrald


THE ENVIRONMENT:

The database has about 18 GB of data.
This is a slave system.
It has 8 Cores and is idle most of the time during the backup.

This is the command I am using:
innobackupex
–user=user
–password=password
–slave-info
–safe-slave-backup
–compress --stream=xbstream ./ |
ssh user@10.0.0.2
“cat - > /data/xtrabackup/2012-05-28_11_37.xbstream”

innobackupex: Starting mysql with options: --password=xxxxxxxx --user=‘user’ --unbuffered –
innobackupex: Connected to database with mysql child process (pid=14380)
innobackupex: Connection to database server closed
IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints “completed OK!”.

innobackupex: Using mysql Ver 14.14 Distrib 5.5.20, for Linux (x86_64) using readline 5.1
innobackupex: Using mysql server version Copyright © 2000, 2011, Oracle and/or its affiliates. All rights reserved.

innobackupex: Created backup directory /root
innobackupex: Starting mysql with options: --password=xxxxxxxx --user=‘user’ --unbuffered –
innobackupex: Connected to database with mysql child process (pid=14410)
innobackupex: Connection to database server closed

innobackupex: Starting ibbackup with command: xtrabackup_55 --backup --suspend-at-end --target-dir=/data/mysql_tmp --compress --compress-threads=1 --stream=xbstream
innobackupex: Waiting for ibbackup (pid=14417) to suspend
innobackupex: Suspend file ‘/data/mysql_tmp/xtrabackup_suspended’

END

The problem I was having is stated at:
https://bugs.launchpad.net/percona-xtrabackup/+bug/1007446

Now that I look at the last line of my original posting, it’s now obvious what the problem was .

Make sure that the /xtrabackup_suspended is not present when starting the backup.