Avago Technologies 3ware SAS 9750-16i4e - Manual (Page 117)

Setting Unit Policies
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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.
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 from the menu bar in
3DM2.
2 In the Unit Policies section of the Controller Settings page, select the
desired Read Cache setting, as shown in Figure 60.
Intelligent: Enables both the Basic and Intelligent Read Prefetch (IRP)
caching features.
Basic: Enables the Basic read caching mode for the unit.
Disabled: Disables the Read Cache policy for the unit.
Table 8: Recommendations for Using Each Read Cache Setting
Use this Read Cache
Setting For this reason Example applications
Intelligent Sequential applications,
with a low host command
queue depth
Video on Demand,
Video Surveillance
Playback
Disk-to-Disk Backup
Restores, File Server
Basic Frequent access to
recently written data Database
Disabled 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. Online Transaction
Processing (OLTP)