SME Server:Documentation:Administration Manual:Chapter4

Chapter 4. Hardware Requirements of the SME Server

The hardware requirements of the SME Server are modest compared with other server software available today. However, because of its critical role in your office, selecting an appropriate host computer is important. The hardware requirements of the host computer depend on such things as the number of users on your network, whether you plan to use the proxy server on the server, and the speed of your Internet connection.

When you consider the requirements, please be aware of the following notes:

• The server ships with the remote access services disabled by default. Enabling webmail will increase the resource requirements of your server, in particular the memory requirement. Other remote access services, such as SSH and PPTP, are also processor-intensive. You should consider a fast processor speed if you intend to make significant use of these services.
• The server should work with any i586 or i686 compatible CPU that can run Centos 4.4.
• The amount of available RAM is one of the most important considerations for server performance as it reduces the load on the disks. If a tradeoff is required, extra RAM will usually be more beneficial than a faster CPU.
• For a dedicated connection in server and gateway mode, your server requires two ethernet adapters (also called network adapters or network interface cards). For a dialup connection or server-only mode, one ethernet adapter is needed.

Note:

Version 7.0 of SME Server is based on CentOS 4.4 and uses the 2.6 series Linux kernel. This combination supports a wide variety of hardware, but it is important that any hardware chosen for the server has been tested for compatibility before deployment. We expect that all hardware which is marked as "Certified" or "Compatible" for RedHat Enterprise Linux Update 4 on the RedHat Hardware Compatibility web site, located at: https://hardware.redhat.com/hwcert/, will function correctly with SME Server 7.0. We do not recommend the use of server hardware which is not listed as "Certified" or "Compatible".

4.1. Minimum Hardware Requirements

The following information outlines what we consider the bare minimum system that will function as a basic file/print server and network gateway. Note that we do not believe such a system will provide satisfactory performance for features such as webmail, remote access via PPTP, Virus and Spam Scanners, which are cpu intensive will not perform well on this platform. To utilize all the features of SME Server 7.0, please have a look at the 'Recommended' Hardware Requirements.

Table 4.1 Minimum Hardware Requirements

Category	Specifications
Architecture	PCI-based i586 or i686 compatible processor
Processor speed	400 MHz
RAM	256 MB
Hard Drive	IDE or SCSI - at least 4 GB
SCSI adapter	SCSI adapter must appear on the supported list (only necessary for SCSI systems)
Ethernet adapter(s)	The ethernet adapters installed on your server must appear on the supported list.
Modem (for dialup only)	Only modems that are Linux-compatible may be used. WinModems are not supported.
CD-ROM drive	ATAPI or SCSI
Monitor	any
Graphics card	any

4.2. Recommended Hardware Requirements

The following information is what we would suggest is the recommended minimum to utilize all the features of SME Server 7.0. How many users this configuration will support depends on how heavily the server will be utilized, but should be sufficient for at least 25 users.

Table 4.2. Recommended Hardware Requirement

Category	Specifications
Architecture	PCI-based i686 compatible processor
Processor speed	1.5GHz
RAM	512 MB
Hard Drive	One or more IDE or SCSI - at least 40 GB
SCSI adapter	SCSI adapter must appear on the supported list (only necessary for SCSI systems)
Ethernet adapter(s)	The ethernet adapters installed on your server must appear on the supported list.
Modem (for dialup only)	Only modems that are Linux-compatible may be used. WinModems are not supported.
CD-ROM drive	ATAPI or SCSI
Monitor	any
Graphics card	any

4.3. Hard Drive Configuration

SME Server 7 introduces a new feature - Automatic configuration of Software RAID 1, 5 or 6. RAID is a way of storing data on more than one hard drive at once, so that if one drive fails, the system will still function. In the case of RAID 6, two drives can fail and the system will still function. We highly recommend that at a minimum you utilize 2 identical drives in your sytem to take advantage of the redundancy provided by the RAID configuration.

Your server will be automatically configured as follows:

• 1 Drive - Software RAID 1 (ready to accept a second drive).
• 2 Drives - Software RAID 1
• 3-5 Drives - Software RAID 5 (4-5 drives with SME 7.1)
• 6+ Drives - Software RAID 6

	Note:
	With SME 7.0 if you utilize more than one drive, they should all be identical in size and model. From SME 7.1 this is no longer a requirement.

4.4. Supported Ethernet or SCSI Adapters, or Tape Drives

Either one ethernet adapter (in the case of dialup connectivity or server-only mode) or two ethernet adapters (for dedicated connections in server and gateway mode) must be installed on your SME Server. Your ethernet adapters must be supported by Red Hat Enterprise Linux 4.

If the computer you plan to use for your server has a SCSI hard disk, your SCSI adapter must be supported by Red Hat Enterprise Linux 4.

If you intend to use the tape backup capabilities of the SME Server, you must have a tape drive that is supported by Red Hat Enterprise Linux 4.