When you need to manage the day-to-day operations of servers and systems, and monitor system performance, configuration, maintenance and repair to ensure that system downtime is minimized and equipment is properly maintained.
ClearOS is a Linux Operating System that is modular and allows for both consolidation and synergy of services. The base ClearOS system is built from source code from Red Hat Enterprise Linux. (ClearOS is not affiliated with Red Hat in any way).
For hardware, virtual and cloud environments, the base requirements are as follows:
Base System
Processor/CPU 32-bit or 64-bit
Memory/RAM At least 1 GB is recommended (see guidelines below)
Hard Disk At least 10 GB is recommended (see guidelines below)
Network Ethernet, cable, DSL
For hardware installs, the requirements are as follows:
Peripherals
Network Cards A network card is required, two for gateway mode
CD-ROM Drive Required for CD installation only
USB Required for USB key installation only
Mouse Not required
Monitor and Keyboard Required for installation only
The following are guidelines for estimating the right hardware for your system. Keep in mind, the hardware required depends on how you use the software.
RAM and CPU 5 users 5-25 users 25-50 users 50-250 users 250+ users
Processor/CPU Low-Power Basic Dual-Core Quad-Core Multi-Core + Multi-Processor
Memory/RAM 1-2 GB 2-4 GB 4-8 GB 8-16 GB 16-32 GB
Hard Disk
Hard Disk Installation and logs require 1 GB - optional storage is up to you
RAID Recommended for mission critical systems
For the most part, hardware that is compatible with the Red Hat Enterprise Linux product will be compatible with ClearOS. For checking compatibility, use the online Red Hat Compatibility Guide. Keep in mind, there are many other hardware products that are compatible – the list is not exhaustive.
All modestly modern hardware includes a compatible CPU. For those installing ClearOS on very old hardware, the CPU requirement is as follows:
Intel architectures from Pentium 6 and onward
AMD architectures from Athlon and onward
Generally, ClearOS does a good job at auto-detecting hardware and most mass-market network cards are supported. ClearBOX also includes wireless support and you can read more about this hardware solution here. Though wireless card drivers are included in ClearOS, wireless is not officially supported in the software version.
ClearOS supports most DSL (including PPPoE), cable modem broadband Internet connections and standard Ethernet connections. ISDN and satellite broadband are not supported unless terminated with a standard Ethernet connection.
RAID Support Overview
Both software and hardware RAID support are available in ClearOS. If you plan on implementing hardware RAID, please read the section below regarding supported hardware. Before you decide to purchase an expensive hardware RAID controller card, consider the following passage from the experts at O'Reilly:
“Software RAID has unfortunately fallen victim to a FUD (fear, uncertainty, doubt) campaign in the system administrator community. I can’t count the number of system administrators whom I’ve heard completely disparage all forms of software RAID, irrespective of platform. Many of these same people have admittedly not used software RAID in several years, if at all.
“Why the stigma? Well, there are a couple of reasons. For one, when software RAID first saw the light of day, computers were still slow and expensive (at least by today’s standards). Offloading a high-performance task like RAID I/O onto a CPU that was likely already heavily overused meant that performing fundamental tasks such as file operations required a tremendous amount of CPU overhead. (…) But today, even multiprocessor systems are both inexpensive and common.” - Derek Vadala - Managing RAID on Linux - O'Reilly
You can implement software RAID in ClearOS by selecting the Create Custom Layout option in the installation wizard. You can find tips and tricks about partitioning in the section Configuring Partitions and RAID.
Some hardware RAID controller cards are not true hardware controller cards. They are simple hard disk controllers with BIOS and drivers to do software RAID Support. If redundancy is your primary concern, then software RAID will serve you better than a quasi-hardware RAID support card. To quote (again) from the Managing RAID on Linux book from O'Reilly:
“The low-end (RAID) controllers are, in essence, software RAID support controllers because they rely on the operating system to handle RAID support operations and because they store array configuration information on individual component disk. The real value of the controller is in the extra ATA channels.”
Supported hardware RAID cards:
Adaptec SCSI - 200x, 21xx, 22xx, 27xx, 28xx, 29xx, 32xx, 34xx, 39xx, 54xx
Adaptec IDE - 2400A
3ware IDE - Escalade 3W 5xxx/6xxx/7xxx
MegaRAID SAS 9240-4i
MegaRAID SAS 9240-8i
MegaRAID SAS 9260-4i
MegaRAID SAS 9260-8i
MegaRAID SAS 9260DE-8i
MegaRAID SAS 9261-8i
MegaRAID SAS 9280-8e
MegaRAID SAS 9280DE-8e
MegaRAID SAS 9280DE-8e
MegaRAID SAS 9280-24i4e
MegaRAID SAS 9280-16i4e
MegaRAID SAS 9280-16i
MegaRAID SAS 8704ELP
MegaRAID SAS 8704EM2
MegaRAID SAS 8708ELP
MegaRAID SAS 8708EM2
MegaRAID SAS 8880EM2
MegaRAID SAS 8888ELP
Unsupported and not recommended:
Most Promise hardware, notably FastTrak100 TX and FastTrak TX2000
HighPoint RocketRAID cards
As a rule of thumb, if a hardware card is under USD $150, then it is probably not true hardware RAID and either not recommended or not supported.
ClearOS run ons dedicated hardware or in your virtual environment in your home, office, or datacenter. Here are some tips when selecting hardware:
Avoid the latest technologies and chipsets. This will reduce the likelihood of compatibility issues and the possible reliability issues that might come with unproven hardware. Avoid desktop systems. You may save a couple of hundred dollars on a desktop system, but they are more likely to fail when used as a server.
Check the vendors web site for Linux compatibility. If you can purchase ServerXYZ with a version of Red Hat Enterprise Linux pre-installed, then the system is very likely compatible with ClearOS.
When it comes to Linux support, some hardware vendors are better than others.
The following vendors ship servers with Linux pre-installed and have a good record when it comes to driver support. You should check the Red Hat Compatibility Guide, especially on any new models.
Dell servers (not desktops)
HP servers
IBM servers
The following vendors have a poor or mixed track record for Linux support.
Promise
Dell Optiplex desktops
Microsoft Hyper-V
