Mac client 2.3.4, windows server 2.3.8, CONN_LOST (10), TIMEOUT (2), backup failed

client macbook pro, 8 gb ram, ssd 74gb free, mac os 10.9.5, urbackup 2.3.4
server windows 2012, 24 gb ram, ssd 190 gb free, backup storage ntfs 21tb free

backup failed frequently for the same files no matter i do to them - move to different folder, rename, change ext, compress to zip etc. result always the same
ERROR: Error getting file patch for “FILENAME” from USERNAME. Errorcode: CONN_LOST (10)
ERROR: Client USERNAME went offline
ERROR: Error getting complete file “FILENAME” from USERNAME Errorcode: TIMEOUT (2)
ERROR: Client USERNAME went offline.

these files are:

  • min found about 48 mb
  • max found about 8 gb
  • different types - pdf, bin, iso, zip, dmg, mov, exe

some files may be completed in 2 or more turns, some files looks like will never be completed.

firewall on server machine allows only incoming tcp 55414-55415 and usual outgoing ports like dns, ftp, http etc.

everything seems to work fine when server’s firewall disabled. any traffic allowed, incoming tcp 55415 and udp 35632, outgoing tcp 35631-35633 connections are visible, in client status menu connection to server indicated as (Internet:No)

if firewall enabled and all these ports allowed server not use it, the only connections are incoming tcp 55415, in client status menu connection to server indicated as (Internet:Yes), issue returns.

sample logs attached, see graylog-pre-2.4.0-rc.2-1.ova backed up in 2 turns. (54.1 KB)

now i found that this issue is not directly related to urbackup. if you catch something similar - check your network and filesystem first.