Child pipe communication closed - stdout.

Symptoms

Scenario #1:

Backup of any Unix server via Linux/MAC DS-Client using Unix-SSH backup sets.

Scenario #2:

Backup of Solaris servers via Linux /MAC DS-Client using Unix-SSH backup sets. When the Unix-SSH backup set is created, provide username and password and "su" to root and root password.

Cause

Scenario #1:

SSH Backup Sets may experience backup failures if the perl/python binary cannot be located using the path environment variable. In previous versions of the software, the DS-Client searched by default for the Perl path in several standard locations. The search for Perl/Python binaries is not performed starting with v.6.2 SP1.

Scenario #2:

a) The sudo is not found on source computer.

b) the csh or tcsh is used on the source computer, shells that are not supported

Workaround

Scenario #1:

Starting with v.6.2 Service Pack 1, this search is not performed (Perl/Python are executed directly) and if the path environment variable is not configured, the SSH backup activities will fail. If you experience such failures, the user has 2 options:

- add Perl/Python in the default search path on the target computer (check that "ssh –l perl" works from the DS-Client machine) or

- configure the Perl’s/Python's full path on the target machine in the backup set's "Advanced Connection" dialog -> "Interpreter/Program path" option.

Scenario #2:

a) Identify the path to sudo:

- Run the command:

which sudo

- Create a soft link to the path returned by the command above( e.g. to /usr/local/bin):

sudo ln -s /usr/local/bin/sudo /usr/bin

b) use sh root@ip_address

your ssh running on a custom port? Can you check in your sudoers file (on the source) if there is the line requiretty? What version of Linux is the source machine?

Configuration:

ssh_config and sshd_config configuration:

In ssh_config (on DS-Client)

add:

ServerAliveInterval 100

ServerAliveCountMax 6

In /etc/ssh/sshd_config

add (or change the values if they exist):

ClientAliveInterval 30

TCPKeepAlive yes

ClientAliveCountMax 99999

Restart the sshd service.

Many routers timeout the connection after some period of inactivity. For users of ssh, this can a big nuisance. In presence of such routers a ssh connection with no activity (for a few minutes) will disconnect automatically. The workaround is that the server and client keep talking to each other. This can be achived using one of the two ways:

Server Side Add the following two lines to /etc/ssh/sshd_config. This will make the server poll for client every 30 seconds. If the client fails to respond for 6 times (i.e., 3 mins), the server will close the connection. Note that this applies to version 2 of OpenSSH only.

ClientAliveInterval 30

ClientAliveCountMax 6

Client Side Add the following two lines to /etc/ssh/ssh_config (or $HOME/.ssh/config if you don't have root access). This will make the client poll for server every 30 seconds. If the servers fails to respond for 6 times (i.e., 3 mins), the client will close the connection. Note that this also applies to version 2 of OpenSSH only. ServerAliveInterval 30

ServerAliveCountMax 6

What does seem to work is to start a continuous ICMP echo request (ping) against the DS-System server.