Read Ahead — On
Normally, the ServeRAID adapter transfers data from disk
to its local cache in steps of stripe-unit size. This provides
excellent overall performance when workloads tend to be
sequential. However, if the workload is random and system
I/O requests are smaller than the stripe-unit size, reading
ahead to the end of the stripe unit will result in lower
performance.
When read-ahead is set to Off, the size of data transfer from
the disk to local cache is equal to the system I/O request
size, and no read-ahead to the end of the stripe unit is
performed.
Notes:
a. You can change the read-ahead setting without destroying
data in a logical drive.
b. When you save the configuration information on a diskette,
the RAID parameters are saved also.
Chapter 2. Configuring Your Disk Arrays
71
Содержание PC Server 330
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Страница 143: ...Preparing to Add Options 11 Remove the adapter retention bracket Chapter 4 Installing Options 129...
Страница 233: ...Completing the Installation 2 Reinstall the adapter retention bracket Slot Chapter 4 Installing Options 219...
Страница 240: ...Updating the Server Configuration 226 PC Server 330 User s Handbook...
Страница 326: ...Resolving Configuration Conflicts 312 PC Server 330 User s Handbook...
Страница 382: ...IBM Part Number 76H8834 Printed in U S A September 1996 76H8834...