Changed DEE-1111 Exam Questions

The correct sequence of actions that take place on a Write Miss is as follows:

• Host sends requests to FE director and no cache slots are found.This happens when the cache is full or the desired cache slot is locked by another request1.
• FE finds available slot by polling.This involves the FE director scanning the cache for an available slot or waiting for a slot to be freed by the BE director2.
• FE sends data from host to mirrored cache locations.This involves the FE director writing the data from the host to two mirrored locations in the cache, one on each engine2.
• FE responds to host to acknowledge successful write.This involves the FE director sending a signal to the host that the write operation is completed, even though the data is not yet written to disk2.
• BE destages data as a high-priority task to make slots available.This involves the BE director flushing some of the existing write pending data from the cache to the disk, in order to free up some cache slots for new write requests2.
• BE destages new data to disk at a later time.This involves the BE director writing the new data from the cache to the disk, according to the destaging algorithm and priority2.

The data characteristics represent an Online Transaction Processing (OLTP) workload profile. OLTP workloads typically consist of a high percentage of small, random I/O operations2. In this case, 80% of the I/O is generated with 8 KB random small blocks, which is characteristic of OLTP workloads2. References: Use DISKSPD to test workload storage performance - Azure Stack HCI | Microsoft Learn

 The symrdf split command is used to suspend SRDF/A replication and make both R1 and R2 devices read/write enabled. This is useful for testing purposes or for creating point-in-time copies of data on both sides. The symrdf establish command can be used to resume SRDF/A replication after a split operation. The exhibit shows that both R1 and R2 devices are read/write enabled and have a Split status, which indicates that a symrdf split command was issued next2

Unisphere for PowerMax and Solutions Enabler have different ways of managing user permissions. Unisphere has a more explicit authentication mechanism for users, where each user must have a username and password to log in to the Unisphere interface. Unisphere also supports role-based access control (RBAC), where each user can be assigned one or more roles that define their level of access to the storage system resources and operations. Unisphere maintains the user and role information in a symauth database, which can be shared with Solutions Enabler. Solutions Enabler, on the other hand, uses the operating system user credentials to authenticate users. Solutions Enabler does not require users to have a username and password to run commands, but it checks the symauth database to verify if the user has the appropriate role to perform the requested operation. Solutions Enabler also supports RBAC, where each user can be assigned up to four roles that define their level of access to the storage system resources and operations.

References:

• Unisphere for PowerMax User Management
• Solutions Enabler User Management