Using Incremental Backup fails.

Hi all.

I Am having some problem with the Incremental backups and i hope that someone can help me here.

I have a DB that no one uses (no active connections).

a base backup was done using "xtrabackup --backup --target-dir=/backup/xtranbackup/full"
The result of cat /backup/xtranbackup/full/xtrabackup_checkpoints is :
backup_type = full-backuped
from_lsn = 0
to_lsn = 421032481873
last_lsn = 421032481873

With out having any change to the DB i have used "xtrabackup --prepare --apply-log-only --target-dir=/backup/xtranbackup/full"

xtrabackup version 1.6.4 for Percona Server 5.1.59 unknown-linux-gnu (x86_64) (revision id: 314)
xtrabackup: cd to /backup/xtranbackup/full
xtrabackup: This target seems to be not prepared yet.
xtrabackup: xtrabackup_logfile detected: size=2097152, start_lsn=(421032481873)
xtrabackup: Temporary instance for recovery is set as followings.
xtrabackup: innodb_data_home_dir = ./
xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 1
xtrabackup: innodb_log_file_size = 2097152
xtrabackup: Starting InnoDB instance for recovery.
xtrabackup: Using 104857600 bytes for buffer pool (set by --use-memory parameter)
InnoDB: The InnoDB memory heap is disabled
InnoDB: Mutexes and rw_locks use GCC atomic builtins
InnoDB: Compressed tables use zlib 1.2.3
InnoDB: Warning: innodb_file_io_threads is deprecated. Please use innodb_read_io_threads and innodb_write_io_threads instead
120208 14:50:52 InnoDB: Initializing buffer pool, size = 100.0M
120208 14:50:52 InnoDB: Completed initialization of buffer pool
120208 14:50:52 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
120208 14:50:52 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Last MySQL binlog file position 0 28855, file name ./lab2-bin.000004

[notice (again)]
  If you use binary log and don't use any hack of group commit,
  the binary log position seems to be:
InnoDB: Last MySQL binlog file position 0 28855, file name ./lab2-bin.000004

xtrabackup: starting shutdown with innodb_fast_shutdown = 1
120208 14:51:07 InnoDB: Starting shutdown...
120208 14:51:07 InnoDB: Shutdown completed; log sequence number 421032482969

the to_lsn = 421032481873 and the log sequence number 421032482969.

according to the doc it should not happen !

If try to apply the Incremental backup(that was done with "xtrabackup --backup --target-dir=/backup/xtranbackup/inc1 --incremental-basedir=/backup/xtranbackup/full ") i get :
120208 15:01:26 InnoDB: Initializing buffer pool, size = 100.0M
120208 15:01:26 InnoDB: Completed initialization of buffer pool
120208 15:01:26 InnoDB: highest supported file format is Barracuda.
InnoDB: ##########################################################
InnoDB: WARNING!
InnoDB: The log sequence number in ibdata files is higher
InnoDB: than the log sequence number in the ib_logfiles! Are you sure
InnoDB: you are using the right ib_logfiles to start up the database?
InnoDB: Log sequence number in ib_logfiles is 421032481873, log
InnoDB: sequence numbers stamped to ibdata file headers are between
InnoDB: 421032482969 and 421032482969.
InnoDB: ##########################################################
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!

so, my question is, what am i doing wrong ?

Thank you, Alon.

update--> after Alexey response i tsrted from the basic, and did the backup using the docs from http://www.percona.com/doc/percona-xtrabackup/xtrabackup_bin/incremental_backups.html?id=percona-xtrabackup:xtrabackup:incremental

the directory did not exist before the backup was started
first backup :
xtrabackup --backup --target-dir=/data/backups/base --datadir=/hddraid/mysql

backup_type = full-backuped
from_lsn = 0
to_lsn = 421032481873
last_lsn = 421032481873

incremental :
xtrabackup --backup --target-dir=/data/backups/inc1 --incremental-basedir=/data/backups/base --datadir=/hddraid/mysql

backup_type = incremental
from_lsn = 421032481873
to_lsn = 421032483039
last_lsn = 421032483039

now the prepare:
xtrabackup --prepare --apply-log-only --target-dir=/data/backups/base

xtrabackup version 1.6.4 for Percona Server 5.1.59 unknown-linux-gnu (x86_64) (revision id: 314)
xtrabackup: cd to /data/backups/base
xtrabackup: This target seems to be not prepared yet.
xtrabackup: xtrabackup_logfile detected: size=2097152, start_lsn=(421032481873)
xtrabackup: Temporary instance for recovery is set as followings.
xtrabackup: innodb_data_home_dir = ./
xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 1
xtrabackup: innodb_log_file_size = 2097152
xtrabackup: Starting InnoDB instance for recovery.
xtrabackup: Using 104857600 bytes for buffer pool (set by --use-memory parameter)
InnoDB: The InnoDB memory heap is disabled
InnoDB: Mutexes and rw_locks use GCC atomic builtins
InnoDB: Compressed tables use zlib 1.2.3
InnoDB: Warning: innodb_file_io_threads is deprecated. Please use innodb_read_io_threads and innodb_write_io_threads instead
120220 17:02:23 InnoDB: Initializing buffer pool, size = 100.0M
120220 17:02:23 InnoDB: Completed initialization of buffer pool
120220 17:02:23 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
120220 17:02:23 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Last MySQL binlog file position 0 28855, file name ./lab2-bin.000004

[notice (again)]
  If you use binary log and don't use any hack of group commit,
  the binary log position seems to be:
InnoDB: Last MySQL binlog file position 0 28855, file name ./lab2-bin.000004

xtrabackup: starting shutdown with innodb_fast_shutdown = 1
120220 17:02:37 InnoDB: Starting shutdown...
120220 17:02:37 InnoDB: Shutdown completed; log sequence number 421032482969

so it looks like i am still doing something wrong, no ?

Alon.