AIX Version 4.3 Differences Guide

6.15 Remote File Distribution Enhancements (4.3.2)
Previous versions of AIX included Version 5.1 of the rdist command, which is
used to distribute and maintain identical copies of files on multiple hosts. The
rdist command on AIX 4.3.2 has been updated to Version 6.1.3, which includes
some new features, namely:
• Multiple target hosts are now updated in parallel. This improves the update
time when working with large numbers of hosts. This behavior can be
controlled by changing the number of hosts updated in parallel, or disabling
the feature, in which case, hosts are updated sequentially.
• The new version of rdist avoids problems when communicating with a remote
host by setting a time-out value. If the remote host fails to respond within a set
period during a transfer, rdist displays an error message and continues to
update other hosts. The previous version of rdist would continue to wait until
the remote host responded.
• Local and remote error messages are distinctly marked for better clarity.
• The amount of free space can optionally be checked to avoid filling up a
filesystem. Before actually installing or updating a file, rdist will calculate
whether the update would exceed the minimum amount of free space as
specified on the command line. If the minimum space would be exceeded by
the update, no update is performed and an error message is displayed.
• The client and server portions are split into two distinct programs, rdist and
rdistd. This lowers the risk of security vulnerabilities since the server rdistd
does not need to be setuid to root. It also allows for greater ease in
maintaining different versions of rdist.
Version 6.1 of rdist implements a new protocol for communicating between
machines. Both versions of the rdist command are shipped with AIX 4.3.2 to
allow users to distribute files to machines running either version of rdist. The
new version is shipped as /usr/bin/rdist, and the old version as
/usr/bin/oldrdist.
When the rdist program contacts a target machine, it requests the target to start
the rdist server side program. Version 6.1 rdist will start the rdistd server
program. Version 5.1 rdist requests the target machine to run rdist -Server. If
the version 6.1 rdist is run with the -Server option, then it will exec a copy of
oldrdist. In this way, you can get compatibility with hosts running rdist Version
5.1 attempting to distribute files to a machine running rdist Version 6.1. If a host
running rdist Version 6.1 wants to distribute files to a host running the rdist
Version 5.1, then it must run the oldrdist program.
6.16 Editor Enhancements (4.3.2)
The ed editor program has been enhanced to examine the environment variable
EDTMPDIR to determine the directory location for temporary files. This has been
done to allow a system to better handle the start up of multiple ed sessions by
avoiding a bottleneck on the inode for the default temporary directory used by ed.
System Management and Utilities 141