
Installing and configuring ServeRAID controllers
193
Stripe-unit size
With RAID technology, data is striped across an array of physical drives. This data-
distribution scheme complements the way the operating system requests data.
The granularity at which data is stored on one drive of the array before subsequent
data is stored on the next drive of the array is called the stripe-unit size.
You can control the stripe-unit size and maximize the performance of your
ServeRAID controller by setting a stripe-unit size to a value that is close to the size of
the system I/O requests. You can set the stripe-unit size to 8 KB, 16 KB, 32 KB, or
64 KB. For example, performance in transaction-based environments, which typically
involve large blocks of data, might be optimal when the stripe-unit size is set to 32 KB
or 64 KB. However, performance in file and print environments, which typically
involve multiple small blocks of data, might be optimal when the stripe-unit size is set
to 8 KB or 16 KB.
The collection of stripe units, from the first drive of the array to the last drive of the
array, is called a stripe.
Supported RAID levels
Disk arrays are used to improve performance and reliability. The amount of
improvement depends on the application programs that you run on the server and
the RAID levels that you assign to the logical drives.
The ServeRAID controllers support RAID level-0, 1, 1E, 5, 5E, 00, 10, 1E0, and 50.
Understanding RAID level-0:
RAID level-0 stripes the data across all the drives in
the array. This offers substantial speed enhancement, but provides no data
redundancy. RAID level-0 provides the largest storage capacity of the RAID levels
that are offered, because no room is taken for redundant data or data-parity storage.
RAID level-0 requires a minimum of one drive and supports a maximum of 16 drives.
The following illustration shows an example of a RAID level-0 logical drive.
Start with two physical drives.
Содержание 86655RY - Netfinity 7600 - 8665
Страница 1: ...IBM Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 2: ......
Страница 3: ...IBM Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 10: ...viii Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 52: ...42 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 104: ...94 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 148: ...138 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 252: ...242 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 270: ...260 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 271: ...Related service information 261 ...
Страница 272: ...262 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 273: ...Related service information 263 ...
Страница 274: ...264 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 284: ...274 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 285: ...Related service information 275 ...
Страница 292: ...282 Hardware Maintenance Manual Netfinity 7600 Type 8665 Models 1RY 2RY ...
Страница 293: ......