Dell PowerVault MD3620i Owner's Manual - Page 35

System Password Reset To reset a forgotten 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 71. 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 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. By default, cache mirroring is enabled in duplex systems and disabled in simplex systems. 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 duplex system configurations with write-back cache and cache mirroring enabled, the write data is always mirrored to the cache of the second controller before completion status is issued to the host initiator. For simplex systems, if cache mirroring is enabled write-back cache is suspended. CAUTION: Running a simplex system with write-back cache enabled, carries all inherent risks associated with a non-redundant system. In case of a catastrophic controller failure, data loss occurs. Planning: RAID Controller Modules 35