Part III Software RAID

The purpose of RAID (redundant array of independent disks) is to combine several hard disk partitions into one large virtual hard disk to optimize performance, data security, or both. Most RAID controllers use the SCSI protocol because it can address a larger number of hard disks in a more effective…

In SUSE Linux Enterprise Server, the Device Mapper RAID tool has been integrated into the YaST Partitioner. You can use the partitioner at install time to create a software RAID 1 for the system device that contains your root (/) partition. The /boot partition must be created on a separate device th…

This section describes how to set up nested and complex RAID 10 devices. A RAID 10 device consists of nested RAID 1 (mirroring) and RAID 0 (striping) arrays. Nested RAIDs can either be set up as striped mirrors (RAID 1+0) or as mirrorred stripes (RAID 0+1). A complex RAID 10 setup also combines mirr…

A degraded array is one in which some devices are missing. Degraded arrays are supported only for RAID 1, RAID 4, RAID 5, and RAID 6. These RAID types are designed to withstand some missing devices as part of their fault-tolerance features. Typically, degraded arrays occur when a device fails. It is possible to create a degraded array on purpose.

This section describes how to increase or reduce the size of a software RAID 1, 4, 5, or 6 device with the Multiple Device Administration (mdadm(8)) tool.

Storage enclosure LED Monitoring utility (ledmon) and LED Control (ledctl) utility are Linux user space applications that use a broad range of interfaces and protocols to control storage enclosure LEDs. The primary usage is to visualize the status of Linux MD software RAID devices created with the mdadm utility. The ledmon daemon monitors the status of the drive array and updates the status of the drive LEDs. The ledctl utility allows you to set LED patterns for specified devices.