D-ISM-FN-01 Sample Questions Answers

To calculate the MTBF, we need to determine the total operational time and the number of failures.

Total operational time (Monday to Friday):5 days × 24 hours = 120 hours

Number of failures:3 (Tuesday, Thursday, Friday)

MTBF = Total operational time / Number of failures

MTBF = 120 hours / 3 = 40 hours

ACDP appliancesits in the data path and:

Intercepts all writesto the production volume.

Splits each write into two copies: one goes to the production volume, the other to the replica volume.

Maintains a journal for point-in-time recovery.

Option A/B/C: These are aspects of replication, but CDP’s primary function is real-time interception and splitting of writes.

FCIP (Fibre Channel over IP) is a protocol used to connect Fibre Channel SANs across geographically dispersed locations over IP networks. It does this byencapsulating Fibre Channel frames into IP packets(Layer 3). This allows FC SAN traffic to be transmitted across IP-based WANs.

Ethernet networks(Layer 2) are not involved in the FCIP encapsulation process directly because FCIP uses IP packets.

Splitting LAN/SAN datais not the method used; FCIP encapsulatesall FC frames.

Separating LAN and SAN dataalso does not describe the tunneling function.

RAID 1isdisk mirroring. It writes identical copies of data to two disks simultaneously, providing redundancy.

Minimum of 2 disks (no parity, no striping).

Excellent read performance, write performance equivalent to a single disk.

Providesfault tolerancebecause data is duplicated.

Anincidentis anunplanned disruptionof a service or a reduction in its quality, often with anunknown root cause.

Incidents require immediate action to restore service.

Example: SAN switch port down, unexpected storage latency.

Support requestsare typically service requests, not incidents.

Impact actionsare more about changes, not incidents.

Events preventing correctionsmight be problems, not incidents.

TheTransport layer (Layer 4)of the OSI model ensures reliable data transfer between systems by providing:

End-to-end connections– manages communication sessions

Sequencing– orders data packets

Integrity– error detection and correction

Session (Layer 5): Manages sessions and controls dialogues between systems.

Data Link (Layer 2): Deals with local network frame delivery.

Presentation (Layer 6): Translates data formats (like encryption, compression).

GRC stands for Governance, Risk, and Compliance. It's a comprehensive framework that helps organizations align their IT operations with business objectives, manage risks effectively, and ensure compliance with internal and external regulations.

GDPR: A specific regulation focusing on data protection and privacy in the EU.

COBIT: A framework for IT governance and management, but not as comprehensive in risk and compliance aspects.

ITIL: Focuses on IT service management, not directly on governance or compliance.

Confidentialityensures that sensitive data is only accessible to authorized users. This is a primary goal of information security, achieved by:

Access controls(authentication, authorization)

Encryptionto protect data in transit and at rest

Monitoring and auditingto detect unauthorized access

Availability:Ensuring data/services are accessible when needed.

Accountability:Tracking actions of users (audit trails).

Integrity:Protecting data from unauthorized modification.

Storage Class Memory (SCM) represents a new class of storage technology that bridges the gap between traditional DRAM and NAND flash memory. SCM offers significantly lower latency and higher endurance compared to NAND flash, making it the highest-performing storage medium currently available. Due to its advanced technology and performance characteristics, SCM is also the most expensive among the listed options.

FC (Fibre Channel):A network protocol used for high-speed data transfer, not a type of disk device.

SATA (Serial ATA):Commonly used in consumer-grade storage; offers lower performance and cost.

SAS (Serial Attached SCSI):Offers better performance than SATA but still lags behind SSDs and SCM.

SSD (Solid State Drive):Provides faster data access than HDDs but is outperformed by SCM.

SCM (Storage Class Memory):Combines the speed of DRAM with the persistence of NAND, offering unparalleled performance.

Data deduplication is a technique that eliminates redundant copies of data, storing only unique instances. When multiple copies of the same data are found, deduplication replaces them with references to a single stored copy, significantly reducing storage requirements.

Data replication:Involves copying data to another location for redundancy, not reducing storage size.

Data encryption:Secures data but doesn't affect storage size.

Data compression:Reduces data size by encoding information more efficiently but doesn't eliminate duplicates.

Dell RecoverPoint is a continuous data protection (CDP) solution that uses journaling to provideany point-in-time recoveryof data. It continuously captures and replicates data changes, storing them in a journal to enable precise recovery to any required point in the past.

Dell SRDF (Symmetrix Remote Data Facility):Provides synchronous/asynchronous replication, not CDP.

Dell TimeFinder SnapVX:Creates point-in-time snapshots but doesn’t offer continuous journaling.

Dell Cloud Tier:Used for archiving older data to the cloud.

In continuous data protection (CDP), journal space stores all the changes made to data over time. The amount of journal space determines the retention window, i.e., how far back in time data can be recovered. A larger journal allows for a longer recovery window.

Amount of space the source and replica volumes require:Relates to storage capacity, not recovery time.

Length of time required to recover the data:Depends on system performance and data size.

Amount of data that can be restored to a specific point:Depends on the changes captured in the journal.

In Ethernet networking, VLANs (Virtual Local Area Networks) are identified using a 12-bit VLAN ID field in the IEEE 802.1Q standard. Since 12 bits can represent 2¹² = 4096 unique values, the maximum number of VLANs that can be supported is 4096.

1024 and 2048: These values are less than the maximum and represent subsets of possible VLANs.

8192: This exceeds the 12-bit limit and is not supported by the standard.

Inwrite-through caching, data is written simultaneously to both the cache and the underlying disk. This ensures data integrity because the write is not acknowledged until it’s safely written to the disk.

Write-backcaching offers reduced latency but increases risk of data loss if cache is lost.

Write-throughtrades speed for security, offeringenhanced data securityand reducing the risk of data loss during power failures.

WWN zoninguses theWorld Wide Names(unique identifiers) of devices (HBAs and targets) to define zone membership.

Offers flexibility: devices can be moved to different ports without reconfiguring zoning.

Common in modern SAN environments.

Port zoninguses physical port numbers for zone membership.

Mixed zoningcombines port and WWN methods.

No zoningwould not segment traffic.