Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 147 — #173

Special Installation Procedures

normal physical hard disks, because the data is duplicated so can be

parallel scanned.

RAID 5 RAID 5 is an optimized compromise between the two other levels

in terms of performance and redundancy. The hard disk space equals

the number of disks used minus one. The data is distributed over the

hard disks as with RAID 0. Parity blocks, created on one of the par-

titions, are there for security reasons. They are linked to each other

with XOR — enabling the contents, via XOR, to be reconstructed by

the corresponding parity block in case of system failure. With RAID 5,

no more than one hard disk can fail at the same time. If one hard disk

fails, it must be replaced as soon as possible to avoid the risk of losing

data.

3.11.2 Soft RAID Conﬁguration with YaST

Access Soft RAID conﬁguration with the ‘RAID’ module under ‘System’ or

via the partitioning module under ‘Hardware’.

First Step: Partitioning

First, see a list of your partitions under ‘Expert Settings’ in the partitioning

tool. If the Soft RAID partitions have already been set up, they appear here.

Otherwise, set them up from scratch. For RAID 0 and RAID 1, at least two

partitions are needed — for RAID 1, usually exactly two and no more. If

RAID 5 is used, at least three partitions are required. It is recommended to

take only partitions of the same size. The RAID partitions should be stored

on various hard disks to decrease the risk of losing data if one is defective

(RAID 1 and 5) and to optimize the performance of RAID 0.

Second Step: Setting up RAID

Click ‘RAID’ to open a dialog in which to choose between RAID levels 0,

1, and 5. In the following screen, assign the partition to the new RAID. ‘Ex-

pert Options’ opens the settings options for the chunk size — for ﬁne-tuning

the performance. Checking ‘Persistent Superblock’ ensures that the RAID

partitions are recognized as such when booting. After completing the con-

ﬁguration, see the /dev/md0 device and others indicated with RAID on

the expert page in the partitioning module.

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SUSE LINUX Enterprise Server