DES-1D12 Sample Questions Answers

Dell is providing native support of NVMe to the midrange of the market, which improves performance.

From the POWERSTORE ADMINISTRATION PARTICIPANT GUIDE,

" Resource balancer also considers the the following when placing volumes:

Whether the appliance is offline

Appliance failure status

Capacity utilization

Dell EMC Flash Storage Efficiency Guarantee Dell EMC promises our flash arrays will provide a logical usable capacity at least four times the usable physical capacity of your purchased drives —or we’ll give you more drives at no charge.https://www.delltechnologies.com/en-us/blog/dell-emc-flash-storage-efficiency/

Dell Unity XT's Host I/O limits feature allows you to set limits on IOPS for individual hosts connected over iSCSI. This can be used to restrict the test/dev hosts to a maximum of 5000 IOPS

An administrator can use a user quota to limit the amount of storage that the user consumes on a Dell PowerStore system. A user quota is a limit that is set on the quota tree, which is a hierarchical structure that organizes storage resources and sets limits on how much storage can be used at each level. The user quota is applied to a specific user or group of users and limits the amount of storage that can be consumed by that user or group of users.

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.

The Skylake CPU family is a 6th generation Intel processor, which provides higher performance and improved energy efficiency compared to its predecessors. It is used on the Dell Unity XT 480, as well as other systems such as the Dell XPS 13, MacBook Pro, and HP Envy. Skylake CPUs are also used in servers, desktops, and laptops. Skylake CPUs include features such as Turbo Boost, Hyper-Threading, and support for DDR4 memory.

A migration import allows data to be transferred from an existing storage platform to a Dell PowerStore cluster. The platforms that support migration import to a Dell PowerStore cluster include Unity, VNX2, Dell EqualLogic PS series and Dell Compellent SC Series. These platforms are EMC storage systems, which are now owned by Dell Technologies.

https://www.dell.com/support/manuals/en-us/powerstore-5000/pwrstr-protect-data/protection-policies?guid=guid-c8ba3ba4-6374-4285-9727-900343f64ee2 &lang=en-us#:~:text=Each%20protection%20policy%20can%20only,up%20to%20four%20snapshot%20rules.

The base enclosure is an all-NVMe platform, capable of supporting NVMe SSD, NVMe SCM, and NVMe NVRAM drives. You can populate slots 0 through 20 with NVMe SSD or NVMe SCM drives. Slots 21 through 24 are reserved for NVMe NVRAM drives which serve as additional system write caching. PowerStore 1000 and PowerStore 3000 models contain two NVMe NVRAM drives in slots 23 and 24.

The reason there is such a large range in the number of IOPS delivered by SSDs is the IOPS are truly dependent on the type of traffic the SC Series was designed to handle. The two biggest factors that will determine IOPS in an SSD environment are block size of the application and overall throughput.

https://dl.dell.com/topicspdf/sc-7-3_rn_en-us.pdf

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.

When sizing a Dell Unity XT 480F using the System Design method, you can select one of four workload types and Drive count and RAID level. This workload type selection will take into account the specific IOPS and capacity requirements of the environment. The drive count and RAID level will determine the overall capacity and level of data protection required.

The embedded module in a Dell Unity XT 480F system provides management functionality for the system, such as control of the storage array, monitoring of system health and performance, and management of storage resources. This embedded module allows you to manage the system through an intuitive web-based interface or via command-line interface.

The System Designer path of the size tool for Dell Unity XT uses predefined configurations that are based on array model capacity points, random workloads RAID type and drive type. This path is designed to make the sizing process quick and easy, providing recommended configurations that are optimized for specific array models and workloads. It allows the user to select an array model, and then it will provide a set of predefined configurations that meet the desired capacity, performance, and availability requirements.

Dell PowerStore supports a variety of NAS protocols to provide file access to clients. These protocols include:

• SMB (Server Message Block): This protocol is used to provide file and printer sharing on Windows-based systems.
• NFSv3 (Network File System version 3): This is a standard protocol used to provide file access on UNIX-based systems.
• NFSv4 (Network File System version 4): This is the latest version of the NFS protocol and it provides enhanced security and improved performance over previous versions.
• FTP (File Transfer Protocol): This is a standard protocol used to transfer files between computers over a network.
• SFTP (Secure File Transfer Protocol): This is an extension of the FTP protocol that provides secure file transfer using SSH (Secure Shell) encryption.

In Dell Unity XT storage systems, a dynamic pool is built using drive partnership groups. A drive partnership group is a group of drives that are combined to create a pool. A drive partnership group can be made up of SAS, NL-SAS, or Flash drives. In this case, the customer has a single pool built from 24x 800 GB SAS Rash 3 drives and 24x 1 6 TB SAS Rash 3 drives, and 14x 400 SAS Flash 2 drives. All drives are SAS type, and it's only one partnership group.

The minimum RPO (Recovery Point Objective) that can be configured on a Dell Unity XT block-asynchronous replication session is 5 minutes. RPO is a measure of how much data can be lost in the event of a disaster, and it's typically measured in minutes. The lower the RPO, the less data can be lost. Block-asynchronous replication is a replication method that copies data blocks, rather than files, between the source and the target. The data is copied at regular intervals, and if a disaster occurs at any point in time, the data on the target will be no more than 5 minutes old. The shorter the RPO, the more frequently data is copied and the less data is at risk of being lost in case of a disaster. It's important to note that this is the minimum RPO for block-asynchronous replication, it can be set to a higher value if needed.

The entire capacity of a particular drive size is only available when the drive count within the drive partnership group for the drive in question matches or exceeds the stripe width plus one drive. It is not recommended to mix different size drives of the same type for this reason, unless an adequate number of drives are available to meet or exceed the stripe width plus one drive requirement

h16289-dell_emc_unity-dynamic_pools.pdf - Page 18-19

https://delltechnologies.techdata.nl/app/uploads/2019/02/dell-emc-unity-xt-selling-guide.pdf

When a Windows client uses the SMB protocol to access a multiprotocol file system from a Dell Unity XT NAS server, the SID (Security Identifier) of the Windows user is mapped to a UID (User Identifier) on the UNIX file system. If no mapping is found in the local group database, the domain controller is checked to see if the SID is present there. The domain controller can provide the information needed to map the SID to the corresponding UID on the file system, allowing the Windows user to access the files. If the SID is not present in the domain controller, the Windows user's access would be removed.

Dell Unity XT systems does not support mixing different drive types in the same RAID group. Adding larger drives to an existing RAID group with smaller drives will cause the operation to fail. The administrator should create a new RAID group with the larger drives and then copy the data from the old RAID group to the new one.

Dell PowerStore 1000T supports the addition of a maximum of one expansion enclosure when it has 10 SCM drives in the base enclosure. An expansion enclosure can be added to the base enclosure and allows the system to support additional drives and increase storage capacity.

The Dell Unity XT 380F has a default spare space allocation of 4% of the total number of drives in a dynamic pool. So with 90x 1.92 TB SSDs, 4 drives will be allocated as spare space. These spare drives are used to automatically replace a failed drive, ensuring data availability and protection.

Common Messaging Interface (CMI): A high speed bus that is used for communication between SPs, such as mirroring write cache or redirecting I/Os from a non-optimized path.

FAST VP (Fully Automated Storage Tiering for Virtual Pools) and FAST Cache (Fully Automated Storage Tiering for Cache) are features that allow you to optimize the performance of your storage by automatically moving data between different storage tiers based on usage patterns. The SSD tier is used to store frequently accessed metadata, such as file system structures, directories, and inode tables, which are accessed frequently and are small enough to fit in the SSD cache. Keeping paged metadata on flash media improves the overall system performance, as it allows for faster access to the metadata, reducing the latency and the number of I/O operations needed to access it.

The assisted migration allows you to move data to a new storage pool with more capacity. This process can be done while the data is still online and accessible to hosts, and it allows you to add or replace drives, expand pools, and move data to a new array without any disruption.

This option provides the smallest drive configuration possible for both the 3000T and 9000T models, and allows for single drive upgrades, which is more flexible for the customer.

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.