Soft Raid Configuration - Novell LINUX ENTERPRISE DESKTOP 11 - DEPLOYMENT GUIDE 17-03-2009 Deployment Manual

By using stripes it is possible to distribute the data stream in the LV among several PVs
(striping). If these PVs reside on different hard disks, this generally results in a better
reading and writing performance (like RAID 0). However, a striping LV with n stripes
can only be created correctly if the hard disk space required by the LV can be distributed
evenly to n PVs. If, for example, only two PVs are available, a LV with three stripes
is impossible.
WARNING: Striping
YaST has no chance at this point to verify the correctness of your entries con-
cerning striping. Any mistake made here is apparent only later when the LVM
is implemented on disk.
If you have already configured LVM on your system, the existing logical volumes can
also be used. Before continuing, assign appropriate mount points to these LVs, too.
With Next, return to the YaST Expert Partitioner and finish your work there.

12.3 Soft RAID Configuration

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 secu-
rity, or both. Most RAID controllers use the SCSI protocol because it can address a
larger number of hard disks in a more effective way than the IDE protocol and is more
suitable for parallel processing of commands. There are some RAID controllers that
support IDE or SATA hard disks. Soft RAID provides the advantages of RAID systems
without the additional cost of hardware RAID controllers. However, this requires some
CPU time and has memory requirements that make it unsuitable for real high perfor-
mance computers.
SUSE® Linux Enterprise Desktop offers the option of combining several hard disks
into one soft RAID system with the help. RAID implies several strategies for combining
several hard disks in a RAID system, each with different goals, advantages, and char-
acteristics. These variations are commonly known as RAID levels.
Common RAID levels are:
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