Rsyncd setup on a windows computer for use with Affa backup

Purpose

Using Cygwin rsync on a Windows computer to backup it remotely over ssh does not work as the Cygwin rsync process hangs. This problem has been reported frequently but was not solved yet. The only known workaround is running the rsync daemon.

This document describes the installation and configuration of the rsync daemon in the cygwin environment on a Windows XP computer for the purpose to backup data using the Affa backup software.

Affa versions 0.9.0 or higher support the rsyncd protocol.

	Note:
	Cygwin requires a Windows OS with NTFS file system. Does not work on FAT32 file system

Installation

Login with the local Administrator account and create a folder C:\cygwin. Save http://cygwin.com/setup.exe to this folder and run it:

Select a nearby mirror

Select the packages to install (in addtion to the already selected defaults):

• from category Net: openssh, rsync
• from category Editor: vim (or any other editor of your choice)
• from category Utils: diffutils

Configuration

Run the Cygwin Bash Shell from the Start Menu.

Configuring the sshd Service

	Note:
	The sshd service is not needed for the Affa backup but it is quite useful to have a ssh login for configuration or viewing log files. You can skip this step, if you don't need ssh login.

Run the sshd configuration script.

ssh-host-config

You are asked a few questions. Answer them as shown in the script dialog below (in bold text).

On Windows Vista

	Incomplete:
	This article or section needs to be expanded. Please help to fill the gaps or discuss the issue on the talk page

.

On Windows XP, Windows 2000 Workstation and Windows 2000 Server

Generating /etc/ssh_host_key
Generating /etc/ssh_host_rsa_key
Generating /etc/ssh_host_dsa_key
Generating /etc/ssh_config file
Privilege separation is set to yes by default since OpenSSH 3.3.
However, this requires a non-privileged account called 'sshd'.
For more info on privilege separation read /usr/share/doc/openssh/README.privsep.

Should privilege separation be used? (yes/no) yes
Warning: The following function requires administrator privileges!
Should this script create a local user 'sshd' on this machine? (yes/no) yes
Generating /etc/sshd_config file
Added ssh to F:\WINDOWS\system32\drivers\etc\services

Warning: The following functions require administrator privileges!

Do you want to install sshd as service?
(Say "no" if it's already installed as service) (yes/no) yes

Which value should the environment variable CYGWIN have when
sshd starts? It's recommended to set at least "ntsec" to be
able to change user context without password.
Default is "ntsec".  CYGWIN=ntsec

The service has been installed under LocalSystem account.
To start the service, call `net start sshd' or `cygrunsrv -S sshd'.

Host configuration finished. Have fun!

On Windows Server 2003

Choose a random string for the password. You'll never need it again.

Generating /etc/ssh_host_key
Generating /etc/ssh_host_rsa_key
Generating /etc/ssh_host_dsa_key
Generating /etc/ssh_config file
Privilege separation is set to yes by default since OpenSSH 3.3.
However, this requires a non-privileged account called 'sshd'.
For more info on privilege separation read /usr/share/doc/openssh/README.privsep.

Should privilege separation be used? (yes/no) yes
Warning: The following function requires administrator privileges!
Should this script create a local user 'sshd' on this machine? (yes/no) yes
Generating /etc/sshd_config file

Warning: The following functions require administrator privileges!

Do you want to install sshd as service?
(Say "no" if it's already installed as service) (yes/no) yes

You appear to be running Windows 2003 Server or later.  On 2003 and
later systems, it's not possible to use the LocalSystem account
if sshd should allow passwordless logon (e. g. public key authentication).
If you want to enable that functionality, it's required to create a new
account 'sshd_server' with special privileges, which is then used to run
the sshd service under.

Should this script create a new local account 'sshd_server' which has
the required privileges? (yes/no) yes

Please enter a password for new user 'sshd_server'.  Please be sure that
this password matches the password rules given on your system.
Entering no password will exit the configuration.  PASSWORD=Xesp348RfnMes

User 'sshd_server' has been created with password 'Xesp348RfnMes'.
If you change the password, please keep in mind to change the password
for the sshd service, too.

Also keep in mind that the user sshd_server needs read permissions on all
users' .ssh/authorized_keys file to allow public key authentication for
these users!.  (Re-)running ssh-user-config for each user will set the
required permissions correctly.


Which value should the environment variable CYGWIN have when
sshd starts? It's recommended to set at least "ntsec" to be
able to change user context without password.
Default is "ntsec".  CYGWIN=ntsec

The service has been installed under sshd_server account.
To start the service, call `net start sshd' or `cygrunsrv -S sshd'.

Host configuration finished. Have fun!

Start the sshd service

net start sshd

Don't forget to open port 22 for the IP address of the Affa server in the Windows firewall.

Testing

ssh Administrator@localhost

Configuring the rsyncd Service

Create the /etc/rsyncd.secrets file and add the user affa with password secretword separated by a colon. Replace the placeholder secretword by a strong password. The user 'affa' does not need to exist on the local system.

affa:secretword

Set secure permissions on /etc/rsyncd.secrets

chown 18.544 /etc/rsyncd.secrets
chmod 660 /etc/rsyncd.secrets

Create the /etc/rsyncd.conf configuration file. Replace the placeholder AFFA_IP by the ip address of your Affa server.

gid = 544
uid = 18
hosts allow = AFFA_IP
auth users = affa
secrets file = /etc/rsyncd.secrets
strict modes = true
read only = true
use chroot = no
transfer logging = true
log format = %h %o %f %l %b
log file = /var/log/rsyncd.log

[AFFA]
path = /cygdrive
comment = cygdrive root dir

Uid 18 is the userid of the System account. Gid 544 is the groupid of the Administrators group (may be shown as root/gid 0 on the Cygwin console).

Install rsyncd as a service.

cygrunsrv --install "rsyncd" --path /usr/bin/rsync --args "--daemon --no-detach" \
 --desc "Starts a rsync daemon for accepting incoming rsync connections" \
 --disp "Rsync Daemon" --type auto

Start the rsyncd service

net start rsyncd 

Don't forget to open port 873 for the IP address of the Affa server in the Windows firewall.

Testing

Login the Affa server and run the following command, where IP_ADDRESS is the IP address of the Windows computer.

rsync -av affa@IP_ADDRESS::'AFFA/'

You should receive a file list of all your drives.

Security

The rsync daemon protocol does not provide any encryption of the data that is transferred over the connection. Use it only in the local net or VPN.

Uninstall

• Login with the local Administrator account and run the Cygwin Bash Shell
• Stop services

net stop sshd
net stop rsyncd 

• Uninstall services

sc delete sshd
sc delete rsyncd

• Remove local user sshd

net user /delete sshd

• Remove local sshd_server (Windows 2003 server only)

net user /delete sshd_server

• Close the Cygwin Bash Shell
• Remove folder c:\cygwin

References

• Affa Contrib
• http://marc-abramowitz.com/archives/2007/10/14/solving-rsync-hangs-with-cygwin/