NEC Express 5800 Series User Manual page 58

Target:
The target can be any valid controller.
Example commands:
controller slot=1 modify surfacescanmode=idle surfacescandelay=3 parallelsurfacescancount=16
controller slot=1 modify parallelsurfacescancount=16
ctrl slot=3 modify pssc=16
Re-enabling a failed logical drive
If a logical drive has failed and the data on it is invalid or non-recoverable, you can re-enable the logical drive
so that it can be reused. This process preserves the structure of the logical drive and merely deletes data,
whereas a delete command applied to a logical drive deletes the logical drive structure as well as the data.
Syntax:
<target> modify reenable [forced]
Example command:
=> ctrl slot=3 ld 1 modify reenable forced
Changing the controller cache ratio
The controller cache ratio setting determines the amount of memory allocated to read and write operations.
Different types of applications have different optimum settings. You can change the ratio only if the controller
has a battery-backed cache (because only battery-backed cache can be used for write cache) and if there are
logical drives configured on the controller.
Syntax:
<target> modify cr=#/#|?
where <target> is a controller, and #/# is the cache ratio in the format read percentage/write percentage.
Example command:
=> ctrl slot=3 modify cr=25/75
Enabling or disabling the drive cache
On controllers and drives that support physical drive write cache, you can use this command to enable or
disable the write cache for all drives on the controller.
CAUTION: Because physical drive write cache is not battery-backed, you could lose data if a
power failure occurs during a write process. To minimize this possibility, use a backup power
supply.
Syntax:
<target> modify drivewritecache=enable|disable|? [forced]
where <target> is a controller that supports drive write cache.
Example command:
=> ctrl slot=5 modify dwc=enable
Enabling or disabling the array accelerator
If the controller has an array accelerator, you can disable or enable it for specified logical drives.
NOTE: Disabling the array accelerator for a logical drive reserves use of the accelerator cache
for other logical drives on the array. This feature is useful if you want the other logical drives to
have the maximum possible performance (for example, if the logical drives contain database
information).
Syntax:
<target> modify aa=enable|disable|?
SSA CLI 58