EMC Interview Questions


Q. Which NetWorker feature enables multiple storage nodes to use the same device?

Dynamic drive sharing

Q. What value has the address space been increased to with the introduction of IPv6?

128 bits

Q. What is the role of a NetWorker storage node?

Manages backup devices

Q. Which protocol is used by open systems hosts to access storage in Fiber Channel SANs?


Q. A read cache miss operation on a Symmetrix has several steps. The first step is that the host sends a read request. What is the next step?

The Channel Director checks the track table.

Q. What are two CLARiioN High Availability features?

Dual LCCs, Dual storage processor

Q. What do VLANs reduce?

The number of packets processed by clients

Q. What does EtherChannel link aggregation do?

Disables links of a different speed to the majority of links in the trunk

Q. What is used by NetWorker to manage its configuration?

Resource directory

Q. What Is Lun Masking in EMC?

LUN (Logical Unit Number) Masking is an authorization manner that makes a LUN to be had to a few hosts and unavailable to different hosts.LUN Masking is applied broadly speaking on the HBA (Host Bus Adapter) stage. LUN Masking carried out at this level is prone to any attack that compromises the HBA. Some storage controllers additionally aid LUN Masking.

Q. Why We Need Lun Masking?

LUN Masking is crucial because Windows based servers attempt to write extent labels to all to be had LUN’s. This can render the LUN’s unusable by way of other working structures and might result in records loss.Device overlaying helps you to manage your host HBA access to sure storage arrays devices. A device masking database, based in the storage arrays unit, eliminates conflicts via centralized tracking and get right of entry to statistics. Both HBA and storage arrays director ports of their Channel topology are uniquely recognized by way of a sixty four-bit World Wide Name (WWN). For ease of use, you can companion an ASCII World Wide Name (AWWN) with each WWN.

Q. How Will You Ensure That San-connected Tape Devices Are Represented Consistently In A Host Operating System?

Use the Persistent Binding for Tape Devices.
Persistent binding is a host-centric enforced manner of directing an working device to assign certain SCSI goal IDs and LUNs.
Persistent Name Binding support is for target devices.
Persistent binding is supplied for customers to companion a certain tool World Wide Port Name (WWPN) to a exact SCSI target ID.
For instance, in which a particular host will usually assign SCSI ID 3 to the primary router it finds, and LUNs 0, 1, and a couple of to the 3-tape drives connected to the router.
Practical examples:For Emulex HBA on a Solaris host for putting in place chronic binding:# lputil
MAIN MENUList Adapters
Adapter Information
Firmware Maintenance
Reset Adapter
Persistent Bindings
Using choice 5 will perform a manual continual binding and the document is: /kernel/drv/lpfc.Conf file.Lpfc.Conf file seems like:fcp-bind-WWNN=”50060XY484411 c6c11:lpfc0t1″,
“50060XY4411 c6c12:lpfc1t2”;sd.Conf record looks as if:
call=”sd” parent=”lpfc” target=1 lun=zero;
name=”sd” figure=”lpfc” goal=2 lun=zero;Reconfigure:# touch /reconfigure
# shutdown -y -g0 -i6

Q. What Is Lun, Logical Unit Number?

Logical Unit Number or LUN is a logical reference to whole bodily disk, or a subset of a bigger bodily disk or disk quantity or portion of a garage subsystem.

Q. What Is Wwn Zoning?

WWN zoning makes use of call servers within the switches to both permit or block get entry to to precise World Wide Names (WWNs) inside the material. A important advantage of WWN zoning is the capability to recable the material without having to redo the quarter records. WWN zoning is vulnerable to unauthorized access, as the zone may be bypassed if an attacker is capable of spoof the World Wide Name of an authorized HBA.

Q. What Is Port Zoning?

Port zoning makes use of physical ports to define safety zones. A user’s access to records is decided through what bodily port he or she is connected to. With port zoning, zone statistics should be updated on every occasion a consumer changes transfer ports. In addition, port zoning does not permit zones to overlap. Port zoning is normally carried out the use of hard zoning, however could also be carried out the usage of soft zoning.

Q. What Is The Difference Between Hard And Soft Zoning?

Hard zoning is zoning that is applied in hardware.
Soft zoning is zoning that is applied in software.
Hard zoning bodily blocks access to a area from any device out of doors of the region.
Soft zoning makes use of filtering applied in fibre channel switches to prevent ports from being seen from out of doors in their assigned zones. The security vulnerability in smooth zoning is that the ports are still reachable if the consumer in another area correctly guesses the fibre channel address.

Q. Explain The Device Masking Architecture In Storage Arrays?

The device covering instructions can help you:Assign and mask get admission to privileges of hosts and adaptersConnected in a Fibre Channel topology to garage arrays and devices.Specify the host bus adapters (HBAs) via which a bunch can get admission to garage arrays devices.Display or list tool overlaying gadgets and their relationships: Typical gadgets are hosts, HBAs, storage arrays gadgets, and Fibre Channel Adapter (FA) ports.Modify properties, along with names and get entry to privileges related to tool protecting gadgets (as an example, trade the Name of a bunch).

Q. How Do You Know What Type Of Fibre Cable Is Needed?

Select it on the basis of transmission distance.If the gap is much less than a couple of miles, I will use multimode fibre cable.If the space is greater than three-five miles, I will use unmarried mode fibre cable.

Q. How Will You Calculate Raw Capacity?

Raw Capacity= Usable + Parity

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