EMC DES-1D12 Specialist - Technology Architect Midrange Storage Solutions Exam Exam Practice Test

The DPE on 480/F, 680/F, and 880/F systems is internally connected to Bus 99 which is a separate bus than the first SAS expansion port that is connected to Bus 0. Therefore, the DPE is recognized by the system as Bus 99 Enclosure 0 while the first DAE connected to the first SAS expansion port would be Bus 0 Enclosure 0. This is different than X00/F, X50F, and 380/F systems. Furthermore, this means that the twenty-five drives in front of the DPE for 480/F, 680/F, and 880/F systems are internally recognized as Bus 99 Enclosure 0 Drive 0 – Bus 99 Enclosure 0 Drive 24. In Unisphere, the drives are seen DPE Drive 0 –DPE Drive 24

The best Unity load balancing method to optimize performance in a customer environment with a limited number of open FC switch ports is Port to Core Affinity. This method will assign the same port to the same core when possible. This allows the same switching resources to be used in the same cores, which will optimize performance due to reduced latency. Priority and Round Robin methods will also provide load balancing, but they are not as effective in a limited port environment. Least I/O is not recommended in this situation, as it will not provide adequate load balancing.

A Dell PowerStore protection policy contains two snapshot rules and one replication rule, and it applies to specific storage resources such as volumes and volume groups. These resources will run only the snapshot rules, not the replication rule. A snapshot rule allows you to create point-in-time copies of the data, which can be used to recover data in case of data loss or corruption. Snapshot rules are applied to specific volumes or volume groups, and only these resources will be backed up with the snapshot. A replication rule allows you to replicate data to a remote site for disaster recovery or data protection. Replication rules are applied to different resources such as Virtual Machines, File Servers, File Systems, etc. In this case, the snapshot rules will be applied to Volumes and Volume Groups, and the replication rule will be applied to other resources such as Virtual Machines, File Servers, File Systems.

"Whether gathering information or designing a system, it is important to understand two commonly used terms: Latency and queue depth"

Synchronous replication will provide a zero RPO as all data is written to both the primary and secondary storage at the same time, which means any data written to the primary storage will be instantly available on the secondary storage. This configuration will ensure that the data is protected against system outage, and in case of any failure, the recovery time will be a maximum of 15 minutes as the data is already replicated to the secondary site.

Dell Unity XT storage pools can be configured to minimize the chance of running out of space due to snapshot utilization by setting high and low watermarks to remove old snapshots. A high watermark is set to specify the maximum amount of space that can be consumed by snapshots before the oldest snapshots are automatically removed. This is a good way to ensure that snapshots do not consume all available space, and helps to prevent the pool from running out of space.

"SCOS 7.3, Distributed Sparing: eliminates the need for dedicated spares by giving customers the option to distribute sparing capacity across all drives in the array."

FAST Cache is an intelligent caching technology that optimizes data access for OLTP workloads by tracking and promoting data at the granularity of 8KB blocks. It uses a combination of flash memory and DRAM to store frequently accessed data, allowing the system to quickly access the most frequently used data, reducing latency and improving overall performance.

Choosing the highest capacity flash drives when designing a Dell Unity XT All-Flash system can provide several benefits, including lower physical space, power and cooling requirements. Additionally, higher capacity drives can also improve system boot time, reduce maintenance and rebuild time, and decrease wear-leveling, performance, and redundancy requirements.

Document: docu71319_dell-emc-unity-high-availability-a-detailed-review.pdf

Page: 20 FAIL SAFE NETWORKING (FSN) Dell EMC Unity OE version 4.2.1 introduces Fail Safe Networking (FSN). FSN is a high availability feature that extends link failover into the network by providing switch-level redundancy. FSN appears as a single link with a single MAC address and potentially multiple IP addresses. FSN can consists of Ethernet ports, link aggregations, or any combination of the two. FSN adds an extra layer of availability to link aggregations alone as link aggregations provide availability in the event of a port failure while FSN provides availability in the event of a switch failure. Each port or Link aggregation is considered as a single connection and only the primary port or link aggregation in an FSN is active at a time. All ports in an FSN must have the same MTU size, but the speed and duplex settings can vary.

Dell PowerStore allows you to create a NAS file sharing environment for several clients by configuring multiprotocol access to the required file system. This means that the same file system can be accessed by both Linux and Windows clients using either the NFS or SMB protocols. This can be achieved by creating a file system, and configuring it to allow access using both the NFS and SMB protocols. Once the file system is set up, you can assign permissions and share the file system with the appropriate clients. This way, the clients will be able to access the same data simultaneously, regardless of whether they are running Linux or Windows and which protocol they are using. It's not necessary to replicate data for access by different client types, it would be an extra step that would consume more resources and would be unnecessary

A storage container is used to present vVol storage from a PowerStore cluster to vSphere. vSphere mounts the storage container as a vVol datastore and makes it available for VM storage. When a PowerStore cluster is used to provide VM storage, user VMs should be provisioned on the vVol datastores. The default storage container is mounted automatically on the nodes of the cluster.

The maximum number of data drives that can be put in to a Dell PowerStore 1000T base enclosure is 21. The Dell PowerStore 1000T has a 2U form factor, and it supports a maximum of 21 drives in the base enclosure. The drives can be either SAS or NVMe, and it's important to keep in mind that the maximum capacity of the system depends on the type of drives that are used. It's important to note that the PowerStore 1000T supports up to 2 expansion shelves that can hold an additional 21 drives each, for a maximum of 63 drives in total. Also, the PowerStore 1000T supports up to 4 NVRAM modules that are used to cache metadata and improve performance.

The PowerStore X model configuration provides a hypervisor layer in addition to block storage.

Reference; https://www.delltechnologies.com/en-ba/collaterals/unauth/white-papers/products/storage/h15089- dell_emc_unity-snapshots_and_thin_clones.pdf (7)