5.2. RAID1 Support (Disk Mirroring)
- 5.2.1. Software Mirroring
- 5.2.2. Hardware Mirroring
With SME Server, you have the ability to set up disk mirroring, also called RAID Level 1. In disk mirroring, you basically write all of your data to two separate hard disks installed in your server. One is the mirror of the other. Should the primary disk experience a hardware failure, the mirror disk will continue operations as if nothing had happened. All of your data will be protected.
Disk mirroring can be accomplished through either software or hardware .
5.2.1. Software Mirroring
To enable software RAID1 support, you must first have two disks that are either the same size or capable of having partitions of the same size. They can be either SCSI or IDE drives. They must both be installed in your system prior to installing the SME Server software. Software RAID support can only be configured at the time you install the software. If you choose not to configure RAID support on your server, and later wish to do so, you will need to reinstall the SME Server software.
Once you have two disk drives, activating RAID support requires only a very slight change in the software installation process as described in section 5.4. Installing the Software.
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SME Server supports a software implementation of RAID Level 1, known as disk mirroring. It does not support RAID Level 0 (disk striping), as that does not provide any protection of your data whatsoever. It does not support RAID Level 5 (disk striping with parity) because of the poor performance and reliability of software implementations of RAID5. If you are seeking RAID5 support, Contribs.org recommends you consider one of the many hardware implementations which will provide both protection and performance. |
5.2.2. Hardware Mirroring
With hardware mirroring, you use a special RAID disk controller to perform the actual mirroring across multiple disks. As mirroring is performed in hardware, the performance can be significantly faster than software mirroring. Additionally it can simplify configuration because to the operating system the entire RAID disk system looks like one single disk. You should be able to use any supported SCSI hardware RAID controller.
If you are going to use hardware mirroring, you should NOT choose Install - Dual hard disk with software RAID-1 mirroring during the installation process described in section 5.4. Installing the Software. (Doing so will enable software mirroring.) Instead, you should do a regular installation of the software.
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Using one of the supported hardware RAID controllers, you will be able to upgrade from an earlier version of the SME Server to version 6.x using the standard upgrade process detailed in section 5.3. Upgrading From A Previous Version. You should back up all your data and test carefully after installation. |