Comment 4 for bug 1007446

We're seeing something similar in 2.1.5 potentially as well. Here is a log exhibiting similar behavior.

 >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    [01] ...done
    >> log scanned up to (284142539120)
    xtrabackup: Creating suspend file '/tmp/xtrabackup_suspended_2' with pid '23557'

    131121 20:13:18 innobackupex: Continuing after ibbackup has suspended
    131121 20:13:18 innobackupex: Starting to lock all tables...
    131121 20:13:18 innobackupex: All tables locked and flushed to disk

    131121 20:13:18 innobackupex: Starting to backup non-InnoDB tables and files
    innobackupex: in subdirectories of '/var/lib/mysql'
    innobackupex: Backing up files '/var/lib/mysql/mysql/*.{frm,isl,MYD,MYI,MAD,MAI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (72 files)
    >> log scanned up to (284142539120)
    innobackupex: Backing up file '/var/lib/mysql/rvr/db.opt'
    innobackupex: Backing up files '/var/lib/mysql/performance_schema/*.{frm,isl,MYD,MYI,MAD,MAI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (18 files)
    innobackupex: Backing up file '/var/lib/mysql/scheduler/db.opt'
    innobackupex: Backing up file '/var/lib/mysql/reporting/db.opt'
    innobackupex: Backing up files '/var/lib/mysql/publisher/*.{frm,isl,MYD,MYI,MAD,MAI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (43 files)
    >> log scanned up to (284142539120)
    131121 20:13:19 innobackupex: Finished backing up non-InnoDB tables and files

    131121 20:13:19 innobackupex: Waiting for log copying to finish

    xtrabackup: The latest check point (for incremental): '284142539120'
    xtrabackup: Stopping log copying thread.
    .>> log scanned up to (284142539120)

    xtrabackup: Creating suspend file '/tmp/xtrabackup_log_copied' with pid '23557'
    xtrabackup: Transaction log of lsn (284142539120) to (284142539120) was copied.
    131121 20:13:20 innobackupex: All tables unlocked

    innobackupex: Backup created in directory '/var/lib/mysql'
    innobackupex: MySQL binlog position: filename 'mysql-bin.001369', position 107
    131121 20:13:20 innobackupex: Connection to database server closed
    131121 20:13:20 innobackupex: completed OK!
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)
    >> log scanned up to (284142539120)