OpenVOS Blog

For an Always-On World

Inconsistent success using public keys

6.3.2013AvailabilityBy: Why is it that from my home directory I can use SSH with public key authentication to log into another host without being prompted for a password?

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OpenVOS Release 17.2.0 is generally available!

4.25.2013AvailabilityBy: I’m pleased to announce that OpenVOS Release 17.2.0, GNU Tools Release 4.0.0 and Kona for OpenVOS Release 1.1.0 are now generally available.  All VOS V Series customers with a maintenance contract are eligible for these releases. Plus, all of them are available on the web site, so you no…

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Remote Command Execution

4.24.2013AvailabilityBy: Last week (well it was last week when I started writing this) we had an issue come into the CAC where someone wanted to write a command macro that ran telnet to log into a system and execute some commands, for example the command macro logins into a remote…

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Update to “Changes in the STCP accept code may affect applications”

4.15.2013AvailabilityBy: About 18 months ago I wrote a blog talking about changes in how accept works in OpenVOS release 17.1. What I neglected to indicate was that these changes only take effect if the application code is POSIX based. To recap, prior to 17.1 STCP would only reply to a client…

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What’s up with VOS structured files and POSIX programs?

3.27.2013AvailabilityBy: If you have ever tried to use POSIX-based programs to process VOS structured files, you may have encountered some restrictions or seen some behavior that you didn’t understand. In this post I will try to explain what’s going on.

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How to access the graphical administrative interface of devices on the maintenance network

3.11.2013AvailabilityBy: The maintenance network is used by OpenVOS for monitoring several devices including the RAID and SAN disk arrays. This network also allows you access for making configuration changes, debugging problems and general monitoring. However, when accessing these devices from the OpenVOS module you can only use the command line interface (CLI); the friendlier, graphical user interface (GUI), used via a web browser is not available.

The lack of a GUI interface has led some of you to connect the maintenance network to another externally available network. This requires that all the devices on the network and the Stratus interface be renumbered. It also means that the devices on the maintenance network will be accessible to anyone with access to the network and the monitoring functions done over the network will be subject to the problems of a much larger network environment. This is something that Stratus strongly urges you not to do.

This post will discuss three ways of allowing you to use the web browser GUI interface to manage these devices while still keeping the maintenance network restricted to just the Stratus module’s environment. The first assumes that you want to gain access from a browser located on the same subnet as one of the Stratus module’s IP interfaces. The next two approaches use SSH tunneling.

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Clone Wars

1.26.2013ProgrammingBy: In this post I wish to discuss a common coding error that can result in a module running out of or at least seriously depleting the available number of stcp device clones for use in creating TCP sockets.

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Telnet versus SSH

1.11.2013Availability, securityBy: A lot of locations are mandating that you stop connecting to the system with Telnet, and use SSH instead. The rationale is greater security. When you log in using Telnet your password, as well as any other data, is sent in clear text. Anyone with a network analyzer can read what you sent. SSH, on the other hand, encrypts all the data making it unreadable. The assumption is that the Telnet and SSH daemons present an interchangeable user experience; this is incorrect.

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Host versus Hosts

11.18.2012AvailabilityBy: There has been a fair amount of confusion over the difference between the host file and hosts (plural) file. Both files should be in the >system>stcp directory but there the similarity ends. The hosts file is used for IP address to name resolution. Depending on your configuration you may or…

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The Importance of -1

10.29.2012Availability, ProgrammingBy: Don’t worry, despite the title I haven’t reverted to math nerd mode. The topic is not number theory but socket programming and a coding mistake that I have seen way too often. The code fragment in figure 1 demonstrates the mistake. There is a main while loop that loops forever…

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