Unable to complete sync using ftpsync : Sync step 2 went wrong

For several months now, we've been unable to complete full syncs of 
debian on our server: ftp.utexas.edu  so I've had to manually refresh 
it. Regardless of the upstream host used we get an error:


ERROR: Sync step 2 went wrong, got errorcode 12. Logfile: 
/home/mirror/logs/ftpsync.log




Am I missing something obvious? I've tried different timeouts but 
sometimes ftpsync ends after 1 hour, other times after almost 2 hours. 
I've tried running ftpsync while other rsync processes were running but 
also when no other rsync is running. I looked through mailing list 
archives but couldn't find any solutions for this.





Information about the server, scripts used, other settings:


ftpsync.log:

Nov 03 10:00:02 marmot ftpsync[19055]: Mirrorsync start
Nov 03 10:00:02 marmot ftpsync[19055]: Running mirrorsync, update is 
required, /var/ftp/pub/debian/Archive-Update-Required-ftp.utexas.edu exists
Nov 03 10:00:02 marmot ftpsync[19055]: Running stage1: /usr/bin/rsync 
--bwlimit=0 -prltvHSB8192  --timeout 7200 ....
.... (rsync options/flags go here)
Nov 03 10:53:50 marmot ftpsync[19055]: Back from rsync with returncode 0
Nov 03 10:53:50 marmot ftpsync[19055]: Latest recorded rsync transfer 
speed: 273 KB/s

Nov 03 10:53:50 marmot ftpsync[19055]: Running stage2: /usr/bin/rsync 
--bwlimit=0 -prltvHSB8192 --timeout 7200 ....
.....(rsync options/flags go here)
Nov 03 11:56:53 marmot ftpsync[19055]: Mirrorsync done
Nov 03 11:56:54 marmot ftpsync[19055]: Back from rsync with returncode 12
Nov 03 11:56:54 marmot ftpsync[19055]: Latest recorded rsync transfer 
speed: unknown KB/s
Nov 03 11:56:54 marmot ftpsync[19055]: ERROR: Sync step 2 went wrong, 
got errorcode 12. Logfile: /home/mirror/logs/ftpsync.log






rsync-ftpsync.error:


rsync: connection unexpectedly closed (342669 bytes received so far) 
[sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(605) 
[sender=3.0.9]
rsync: connection unexpectedly closed (174346326 bytes received so far) 
[receiver]
rsync error: error in rsync protocol data stream (code 12) at io.c(600) 
[receiver=3.0.6]
rsync: connection unexpectedly closed (20506338 bytes received so far) 
[generator]
rsync error: error in rsync protocol data stream (code 12) at io.c(600) 
[generator=3.0.6]






Server:
Red Hat Enterprise 6.7 64-bit




rsync:

Name	:  rsync
Version	:  3.0.6	Vendor: Red Hat, Inc.
Release	:  12.el6	Build Date: Fri 28 Mar 2014 05:58:13 AM CDT






Script used:

ftpsync
VERSION="20150425"




Contents of ftpsync.conf:

MIRRORNAME=ftp.utexas.edu
TO="/var/ftp/pub/debian"
RSYNC_PATH="debian"
RSYNC_HOST=mirrors.kernel.org
LOGDIR="/home/mirror/logs"
[email protected]
ERRORSONLY="false"
FULLLOGS="true"
EXCLUDE="--exclude=squeeze* --exclude=Debian6*"
ARCH_EXCLUDE="alpha hppa hurd-i386 kfreebsd-amd64 kfreebsd-i386 m68k 
mipsel mips powerpc s390 s390x s390"
LOGROTATE=21
TRACE="project/trace/${MIRRORNAME}"
RSYNC_FILTER="--filter=protect_Archive-Update-in-Progress-${MIRRORNAME} 
--filter=protect_${TRACE} 
--filter=protect_Archive-Update-Required-${MIRRORNAME}"
RSYNC_OPTIONS="-prltvHSB8192 --timeout 7200 --stats ${RSYNC_FILTER}"


(full logs were only enabled 2 days ago)






Oscar