VERITAS Volume Manager 4.1 Administrator's Guide

Performance Monitoring and Tuning

Performance Guidelines

Chapter 12396

Striping

Striping improves access performance by cutting data into slices and

storing it on multiple devices that can be accessed in parallel. Striped

plexes improve access performance for both read and write operations.

Having identiﬁed the most heavily accessed volumes (containing ﬁle

systems or databases), you can increase access bandwidth to this data by

striping it across portions of multiple disks.

The ﬁgure “Use of Striping for Optimal Data Access” shows an example

of a single volume (HotVol) that has been identiﬁed as a data-access

bottleneck. This volume is striped across four disks, leaving the

remaining space on these disks free for use by less-heavily used volumes.

Figure 12-1 Use of Striping for Optimal Data Access

Mirroring

NOTE You may need an additional license to use this feature.

Mirroring stores multiple copies of data on a system. When properly

applied, mirroring provides continuous availability of data and

protection against data loss due to physical media failure. Mirroring

improves the chance of data recovery in the event of a system crash or

the failure of a disk or other hardware.

HotVol HotVol

PL1 SD3

Another

Disk 1 Disk 2 Disk 3 Disk 4

HotVol

PL1 SD4

Less

Important

Volume

HotVol

PL1 SD2

Lightly

Used

Volume

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