LSI 3ware 9750 User Manual page 117

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When to Use Each Read Cache Setting
The following table provides some recommendations for when to use each
Read Cache setting.
Table 8: Recommendations for Using Each Read Cache Setting
Use this Read Cache
Setting
Intelligent
Basic
Disabled
Changing the Read Cache Policy for Existing Units
The Read Cache policy is initially set when you create a unit. You can change
it later from either 3DM2 or 3BM.
To change the Read Cache unit policy In 3DM2
1 Choose Management >> Controller Settings
3DM2.
2 In the
Unit Policies
desired Read Cache setting, as shown in Figure 60.
Enables both the Basic and Intelligent Read Prefetch (IRP)
Intelligent:
caching features.
Enables the Basic read caching mode for the unit.
Basic:
Disables the Read Cache policy for the unit.
Disabled:
For this reason
Sequential applications,
with a low host command
queue depth
Frequent access to
recently written data
Applications that produce
a high queue depth or
perform their own read-
ahead can generate
enough I/O to negate the
benefits of controller read
caching or read-ahead.
This is especially true for
applications that produce
a lot of random I/O.
section of the Controller Settings page, select the
Setting Unit Policies
Example applications
Video on Demand,
Video Surveillance
Playback
Disk-to-Disk Backup
Restores, File Server
Database
Online Transaction
Processing (OLTP)
from the menu bar in
105