Symptoms

Avamar NDMP is backing up to an Isilon IP address.The avndmp log shows the avndmp process proceeding as normal, completing the pre-backup handshake on its IP and control port 10000.The Isilon NDMP process sends the Avamar avndmp process an IP address and a port # for the data for data transfer. The backup starts and the avndmp process the message: "Unable to establish data connection to address" is seen. 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] BASE_DATE=0 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] Backup attribute bits set: FILELIST DIRECT INCREMENTAL UTF8 FH_FILE FH_DIR 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] Recover attribute bits set: FILELIST DIRECT INCREMENTAL UTF8 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] NDMP server information: Isilon Isilon NDMP 2.3.0 auth_types: [text md5] 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] Querying filer supported extension list 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] extension class id: 0x2050, extension version: 2 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] NDMP listening IPV4 for data on address 10.xxx.xxx.20, port 29940 2016-11-27 14:02:51 avndmp Info : [snapup-/ifs] Connecting to data socket on address 10.xxx.2xxx.20, port 29940. 2016-11-27 14:03:12 avndmp Error : [snapup-/ifs] Unable to establish data connection to address 10.xxx.xxx.20, port 29940. 2016-11-27 14:03:12 avndmp Error : [snapup-/ifs] Backup for target /ifs had errors. 2016-11-27 14:03:12 avndmp Info : [snapup-/ifs] Backup of '/ifs' aborted. Error in NDMP session. 2016-11-27 14:03:12 avndmp Info : [avndmp_assist] Thread exited with errors: /ifs

Cause

Part of the NDMP pre-backup handshake process is for the remote NDMP protocol to return an IP address and port number through which data should be transferred.When connecting to Isilon, the NDMP protocol returns the first IP in the pool used by NDMP.This IP can be on a different subnet, virtual lan, etc. and not accept connections to the IP address and port returned to Avamar.It is important to verify that the IP address is correct for the communications to proceed on.Cause 1: - smartconnect nameWhen the smartconnect name is used instead of the IP address, the first pass gives the control IP, and the handshake succeeds.When avndmp ties to connect to the data port, it can be a different IP than that expected by the Isilon NDMP.Cause 2: - zoningThere is also an issue when using zoning, the returned IP is the fist one in the Zone. If this IP is not accessible by the accelerator node, the backup fails.Cause 3: - firewall With the release of 7.2, often avfirewall is installed. It may block ports needed by certain services.

Resolution

Cause 1: - smartconnect nameTry using an IP instead of the Smart Connect name. NOTE: The address avndmp tries to connect to the Isilon on is not under Avamar control. It is sent as part of the NDMP handshake process and is controlled by the Isilon. It must be resolved by the Isilon Administrator. Cause 2: - zoningCheck with the Isilon Administrator.The Isilon administrator should check to make sure the correct IP is being sent to Avamar.Cause 3: - firewall As a test, try turning off avfirewall.As root, run systemctl restart avfirewall.Test the backup.If the firewall is the problem, it can be edited to allow NAS traffic.Follow the instructions from https://www.dell.com/support/kbdoc/000019911. This is the preferred method to configure the avfirewall post Avamar 7.3. Configuration settings WILL remain after an upgrade.

Support Cases