Dell PowerVault MD3220i Owner's Manual - Page 35

Table 3-1. Shutdown Threshold Type Threshold Temperature Exceeding Event Description Nominal failure threshold A critical event is set Maximum failure threshold Shutdown of the system power supplies occurs within three minutes Shutdown threshold Shutdown of the system power supplies occurs within five seconds System Password Reset The storage array system password can be reset if it is forgotten. To reset the password, push and hold down the password reset switch for at least 5 seconds. The password is deleted. See Figure 3-1 to locate the password reset switch. The RAID controller module allows you to change the password. For more information about setting your password, see "Setting a Password" on page 69. NOTE: The reset switch can be accessed by using a small object such as the tip of a pen. Cache Functions and Features Cache Mirroring Cache mirroring function copies accepted host-write data from the primary controller to the partner controller. This action ensures that host-write data is safely mirrored to the partner controller before successful completion status is returned to the host. If a controller fails, the surviving controller safely retains all mirrored data. Cache mirroring is enabled by default. Write-Back Cache In Write-back Cache, write operations result in a completion signal being sent to the host operating system as soon as the cache receives the data to be written. The target physical disk receives the data at a more appropriate time in order to increase controller performance. In dual-active controller configurations with Write-back Caching enabled, the write data is always Planning: RAID Controller Modules 35