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Choice of operating system on managed machines
There is a certain amount of choice in the operating system available on Lab managed machines. This page summarises the available options.
Members of the laboratory will be allocated a desk, and a computer of some sort will be provided there; we refer to this computer as your desktop machine. Your desktop machine should be the main computer that you use, but it is not necessarily the only one. It will run some variety of Linux, Windows, or MacOS X. You will be able to use your desktop machine to login remotely to a number of time sharing machines within the laboratory running various variety of Linux or Windows. So, whichever operating system your desktop machine is running you will be able to use machines running some other operating system.
You may choose which Operating System your desktop machine runs.
Your choice may be influenced by a number of factors: you may need a particular system for your work; you may have previous experience of one system or another; or you may want to use a system that your colleagues suggest. (It may be useful to discuss the matter with your supervisor; also, see distinguishing Linux features below.)
The choices available are listed below.
You will be given an account, which is the right to login to a particular set of machines. This will initially include the publicly available machines, and those in your group (which of course includes your own desktop machine). All machines authenticate using a shared Kerberos server, hence you only need one password, whatever managed machine you are going to log in to.
You will have normally local administrator access to your desktop machine. (Of course, if you irrevocably ‘break’ your machine by exercise of those privileges, the department offers no support — your machine will be ‘cleaned’ and the operating system reloaded.)
The following operating systems are available for use on your desktop machine:
Linux
The laboratory supports Redhat and Ubuntu, both of which offer "stable" and "bleeding edge" versions. Redhat has CentOS (a free rebuild of Redhat Enterprise Linux) and Fedora (not supported here), whereas Ubuntu has the "LTS" and six monthly updated versions. In each case, the system aims as far as possible to be a simple “out of the box” installation: the criterion for altering things is purely to make the system interact comfortably with the laboratory infrastructure (such as printers, and the file servers which house your home directory among many other things), provide a "standard" set of packages, and to protect the security of the system.
All Linux systems are provided with a default set of packages installed; you can add further packages from local repositories with little fuss. Security updates and the like will be provided as seamlessly as possible.
At the start of 2009, we moved to using krb5 NFS security. Logging in to the machine remotely is trickier, and long running (relatively straight forward up to a week) and cron jobs may have problems accessing the NFS server (if only local filestore is used, these should not be problems). Consider using a time sharing system if there are problems.
The distinction between Ubuntu and Redhat, stable and bleeding edge
The distributions offer similar facilities. They share most of their Open Source Software source code, but the packages may be of different forms (RPM or .deb), built with different options, and they may have different versions.
The Redhat versions, CentOS and Fedora, have the same look and feel as they are based on the same code options, with Fedora acting as a testing ground for the more stable CentOS. As of 2011, Fedora does not manage to interwork with our central services, so is not supported.
Ubuntu has a slightly different look and feel as it uses different code options. It uses time based releases where a new version is produced every 6 months (normally April and October). Most of these are supported for three cycles (18 months). Every two years (normally April of even years), a "Long term Support" version is brought out, which is supported for around two cycles (3 years for the "desktop" version, 5 years for the "server" version).
As of 2011/09 there appears to be a "feature" with the bleeding edge usb3 code such that the driver blocks suspend working. This means that if the backstop code to detect idle machines thinks that a machine is not in use, it will fail to suspend the machine, so will have to shut it down, losing any state. As such, if there is no particular reason to do otherwise, selecting the stable version might be better.
Whilst all systems are maintained continuously, the "stable" systems, Ubuntu LTS and CentOS, have a much slower cycle of major releases than the "bleeding edge" versions of Ubuntu. A PhD student selecting a "stable" system should be able to use the same system for three years without requiring an upgrade. Those selecting "bleeding edge" are likely to want to keep up with the latest version, with a rolling upgrade to the latest version (either "early" in the cycle to try the latest features, or "late" to wait til teething problems are sorted). There may be pressure to upgrade if a system is no longer supported and there is a security problem with the system. Permanent members of staff are likely to require either rolling upgrades, or occasional reinstalls.
Laptops and other machines which may not always have access to the Lab infrastructure can be managed in a very similar way, but do not normally use Lab facilities such as fileserver, LDAP and Kerberos.
When selecting which distribution, you may care to consider:
- Whether a particular distribution is needed by your work
- Which distribution is used by others working in your field
- Any previous experience you have of the distributions
- Whether you want the latest and greatest bleeding edge or very stable code
Windows
We offer 64b Microsoft Windows 7 on laboratory managed desktop machines. The system installed is pretty much as supplied by Microsoft; access to the file server and to the printers is not significantly different from what you would expect from any networked windows system.
A wide range of software is provided for installation, but we cannot guarantee that we can make every commercial product freely available – research group funds may need to pay for some packages.
MacOS X
As of 2009, users can opt for a Mac instead of a PC, but note that as this is cost-neutral, the spec of the machine is likely to be less that than of the standard PC.
MacOS X can access the filer (using CIFS), the departmental printers, and setup a VPN.
Note that users are expected to manage the machines themselves, and support is minimal.
Other Systems
Users who are used to running other systems may be able use them, so long as they can access the departmental filer using per user Kerberos authentication e.g. "sec=krb5" NFS or CIFS. Note that the level of central support for such systems is less than for those listed above, and that if there are problems it may be necessary to reload the system from scratch.
The deal on dual boot
We strongly discourage those who ask for the installation of multiple operating systems (dual booting) on their desktop machines. This is a practical matter: while dual boot sometimes necessary on home machines, it is often no more than an “time sink” in a well-provisioned work place. If you are a software developer both under Linux and Windows, you will be able to persuade administrators of your needs.
If you need more than one operating system on your computer, you may be able to use a suitable virtualisation technologies. We also have a pool of Xen Enterprise servers on which virtualy machines can be hosted.