Silicon Graphics InfiniteStorage 4000 Series, Настройка и обслуживание

Страница: 199 / 276

Chapter 11: Maintaining a Storage Array 187
Changing the RAID
Levels
When you create a volume group, you can define the RAID level for the volumes in
that volume group. You can change the RAID level later to improve performance or
provide more secure protection for your data.
NOTE
RAID Level 6 is a premium feature for the CDE3992 controller-drive tray,
CDE3994 controller-drive tray, and the CE4900 controller-drive tray. You must enable
RAID Level 6 with the feature key file before you can use the Dynamic RAID-level
Migration feature.
To change the RAID level, use this command:
set volumeGroup [ volumeGroupNumber ]

raidLevel=(0 | 1 | 3 | 5 | 6)
In this command,
volumeGroupNumber
is the number of the volume group for
which you want to change the RAID level.
Changing the
Segment Size
When you create a new volume, you can define the segment size for that volume. In
addition, you can change the segment size later to optimize performance. In a
multiuser database or file system storage environment, set your segment size to
minimize the number of drives that are needed to satisfy an I/O request. Use larger
values for the segment size. Using a single drive for a single request leaves other
drives available to simultaneously service other requests. If the volume is in a
single-user large I/O environment, performance is maximized when a single I/O
request is serviced with a single data stripe; use smaller values for the segment size.
To change the segment size, use this command:
set volume ([ volumeName ] | < wwID >)
segmentSize= segmentSizeValue
where
segmentSizeValue
is the new segment size that you want to set. Valid
segment size values are
8
,
16
,
32
,
64
,
128
,
256
, and
512
. You can identify the
volume by name or by WWID. (For usage information, refer to the
set volume
command in the
Command Line Interface and Script Commands for Version 10.75
.)
Changing the Cache
Parameters
The script command set provides two commands that you can use to change cache
parameter settings:
 set storageArray
 set volume
The
set storageArray
command lets you change settings for these items:

The cache block size

The cache flush start percentage

The cache flush stop percentage