Enterprise linux is being offered by the three major commercial linux distributions; RedHat, SUSE and Mandrake. Here is what each says the purpose of it's enterprise product is.
RedHat says it's enterprise offering (RedHat Enterprise Linux 3, RHEL) is: a reliable, secure, high performance platform designed for today's commercial environments. This product has a long release cycle (12-18 months), and a long support cycle (supported by RedHat for 5 years).
SUSE touts it's enterprise product (SUSE Linux Enterprise Server 8, SLES) as: a server-optimized version of the vendor's Linux distribution. It represents a continuation of the company's tradition of producing solid product, with the added value being a level of consistency and portability up and down the enterprise food chain -- it provides the same APIs and basic layout running on anything from a humble commodity server to an IBM mainframe. SUSE also has a 5 year support cycle and a release cycle of 24 months.
Mandrake bills it's enterprise edition (Mandrake Linux Corporate Server 2.1) as: a complete 'all-in-one' enterprise solution that includes everything needed to rapidly deploy world-class Linux server applications in the enterprise.Mandrake has a 12 month release cycle, but I couldn't find a hard time frame for a support cycle.
So basically, the concept of an enterprise linux offering is that you have a fairly long time between releases (12-24 months) and a product that remains supported for an even longer period of time than the release cycle. This allows for stable server deployments with guaranteed bug fixes and security updates for an extend period of time (up to 5 years).
For businesses with custom server applications, like Enterprise Resource Planning (ERP) or Customer Relationship Management (CRM) databases and associated applications, this can greatly increase stability and greatly reduce costs. Before the enterprise offerings, when the security updates stopped for a product, it was time to upgrade ... and that could be as frequently as every 12 months. Now that same business can expect bug fixes and updates for 5 years, meaning now normal application upgrades can drive the process, and not the need to upgrade your operating system.
This sounds pretty good, but how much does it cost? Since it is released less frequently (so there is less sales in a 5 year period) and it must be supported for a longer period of time, it stands to reason it will be more expensive than the standard offerings. Here are the current prices (in US dollars) for support, security updates, and bug fixes:
$1499 – OS Updates, phone support 9-9 ET M-F(within 4 hours), 24/7 web support (within 2 days)
$2499 – OS Updates, 24/7 Phone Support (1 hour), 24/7 web support (within 1 day).
$799.90 – updates and up to 5 support incidents
$1649.90 – updates and unlimited number of incidents
$999.00 - Updates and e-mail support
$1499.00 - Updates and phone support
Are there any community related projects based on Enterprise products?
So, for a price, you can have a stable release for an extended period of time. Now the real question ... can I get a good enterprise linux release, for free, that meets some of these criteria (Of course, there is no phone support or official web support for the free products). The answer is ... Yes. There are 4 products available (or soon to be available) that have goals to meet these requirements. Three of these are RPM based distributions built from the RedHat Enterprise Linux 3 source RPMS, the other is based on Debian.
I have installed each of these products, and they all will fit the bill. The product based on Debian is called UserLinux. It is not yet released, but it merits attention and will soon be a legitimate player in this category.
The other three products are discussed in more detail below. They are each built from the released source code from RedHat Enterprise Linux 3. I would like to thank RedHat for releasing this code and for releasing the source code for their updates and bug fixes when they release the actual fixes. Their continued support of the Open Source community makes quality products like these available.
Tao Linux - This distribution has 3 Binary ISOs that are downloadable from 4 sites. It is updated by yum as RedHat releases updates. It installs and feels very much like RHEL 3 AS. The mailing lists are growing and user support is getting better with this product. There are install versions for x86 (Intel, AMD Athlon, Cyrix), X86_64 (Athlon 64) and S/390 (IBM) type servers, making this the distribution that supports the most architectures. As the user community for this distribution grows it will be extremely formidable. The x86 support is provided mainly by David L. Parsley (the original developer) and the X86_64 and S/390 discs/updates are built by Pasi Pirhonen. This is a good distribution, but it's not the one I use. Overall, it is a good product.
WhiteBox Enterprise Linux - This distribution is also 3 binary ISOs. It can be downloaded from 5 mirror sites and bittorrent. It is updated via either a custom up2date or yum. It also installs and feels very similar to RHEL. Updates are also provided when the source code is released from RedHat. There are versions for x86 and X86_64. The mailing lists from this distribution are currently the most active. This distro is also built and supported by one person, John Morris. There is also a user website with a forum called WhiteBoxLinux.net. This is the version that I use. I have it installed on several production boxes, including my main workstation at home and at work. Currently, I recommend this distribution.
CentOS - This distribution is a part of the bigger cAos project. It has a large group of developers, not a single builder like the other projects. Because of that, it was slower to release it's first set of ISO's. However, it now has a rebuilt ISO that includes updates up to 3/18/04 ... meaning the first updates done after install are completed much faster (since many are installed with the original install). This is not the case for either WhiteBox or Tao. Those installs are based on the original RHEL source, and there are more than 100 updates done on the first update after install. This is probably the most promising of all the community based RHEL rebuild enterprise projects. I might be installing more of this distribution soon.
Enterprise Linux installs offer longer release cycles and extend lifetimes for users and businesses who need a stable platform for periods longer than the standard linux distributions. The full supported versions from RedHat, SUSE, and Mandrake are similar in function, support and price; and they are very good for users who require support with their install and are willing to pay for that support.
For those of us who need longer release cycles and support cycles in a free community type project, the 4 products reviewed can fill that gap on our server machines.
Release Cycle - How often a new product version will be released.
Support Cycle - How long security and bug fixes will be released for a product.
Update: Here is Red Hat Enterprise Linux Rebuild mini-HOWTO for those interested to brew their own RHEL based linux.