2012年11月19日网络存储复习.doc

1. which local replication technology does emc timefinder/mirror implement?a. copy on first accessb. copy on first writec. full volume mirroringd. pointer basedanswer: c2. which logical component of a storage environment is host resident?a. memoryb. portc. diskd. file systemanswer: d3. a customer requires a local replica of a database that must remain available on a 24*7 basis. the application consistent replica of the file system, which operation should be performed?a. stop the application prior to the creation of the replicab. quiesce and flush the file system buffers before the creation the replicac. unmount the file system prior to the creation of the replicad. quiesce and flush the file system buffers after the creation of the replicaanswer: b4. what is an advantage of reporting on storage arrays?a. planning for storage groupb. monitoring number of arraysc. planning for capacityd. monitoring number of disks in a raid groupanswer: c5. what is the sequence of steps in a business continuity planning process?1. perform risk analysis2. collect data on various business processes3. test, train and maintain4. develop a disaster recovery plana. 3-4-1-2b. 2-3-1-4c. 2-1-4-3d. 3-2-1-4answer: c6. what does a pull operation in san based remote replication indicate?a. data is pulled to one remote array from another remote arrayb. data is pulled to the control array from remote arrayc. data is pulled to one control array from another control arrayd. data is pulled to the remote array from control arrayanswer: b7. a customer wants to deploy business continuity solution between to data center which are 500 km apart which solution want to connectivity between the two fc-sans in the most cost-effective way?a. ip switches communicating over tcpb. fc switches communicating over fcpc. native iscsi communicating over tcp/ipd. fcip gateways communicating over tcp/ipanswer: d8. in full volume mirroring when is the target accessible?a. only after synchronization and detached from sourceb. only before initial synchronization and detached from sourcec. only before initial synchronization and attached to sourced. only after synchronization and attached to sourceanswer: a9. how many devices can be connected to a storage array in a point-to-point configuration?a. 2b. depends upon number of array portsc. 15 million devicesd. 127answer: a10. how many domain ids are reserved in fibre channel address space?a. 16b. 239c. 256d. 17answer: b11. what is a feature of pointer-based virtual replication?a. source need not be healthy for restoreb. reduction in storage requirement for the replicasc. replica can not hold more than 30% of the changed datad. source can not hold more than 30% of the changed dataanswer: b (p87)12. how does asynchronous remote replication improve application performance compared to synchronous remote replications?a. reads are serviced by the remote replicab. reads are serviced by the sourcec. writes are acknowledged immediately by the remote replicad. writes are acknowledged immediately by the sourceanswer: d13. which describes a feature of internal das?a. local storage provisioningb. high cpu utilizationc. high scalabilityd. array based managementanswer: b14. in an intelligent disk system, what is the role of the back-end?a. to move data between a host and the array cacheb. to communicate between tag ram and data storec. to communicate between a host and the storage systemd. to move data between an array cache and the disksanswer: d15. which raid type is most suitable for an application with large sequential reads?a. raid 5b. raid 3c. raid 1d. raid 0answer: b (p18)16. which three subject areas taken together define storage security?a. access control, information security, and networkingb. access control, encryption, and networkingc. encryption, networking, and storaged. information security, networking, and storageanswer: d17. a business wants to backup 1 tb of data containing 100,000 files and another 1tb of data containing 1 million files. which write need more time ?a. number of files is irrelevantb. both will take same timec. 1 million filesd. 100,000 filesanswer: d18. what are five core elements of a data center infrastructure?a. applications, databases, servers/operating system, san, and jbodb. applications, databases, jbod ,networks, and storage arraysc. applications, databases, servers/operating system, dan, and nasd. applications, databases, servers/operating system, networks, and storage arraysanswer: d19. what is a characteristic of parity-based raid?a. parity is updated each time when both read and write are performedb. parity is read each time a read is performedc. parity is updated each time a write is performedd. parity is updated only when writes fill a stripeanswer: c20. what is the data access pattern that is most affect by slow seek times?a. random, small writesb. sequential, small readsc. random, large readsd. sequential, large writesanswer: a21. which term refers to the writing of physical address information to a disk?a. stripingb. partitioningc. file system mountingd. formattinganswer: d22. a customer complains about frequent traffic disruptions to their san. after analysis, it was found that the r&d group was created a application traffic while testing new products. what would you suggest that this customer implement?a. server virtualizationb. virtual sanc. storage virtualizationd. virtual lananswer: b23. which statement is true about c-clip?a. a virtual package that contains mete-data and blobb. a virtual package that contains cdf and blobc. a virtual package that contains ca and blobd. a virtual package that contains c-clip id and blobanswer: a24. how can the exposure to loss of uncommitted cached data be minimized?a. write-backb. watermarkingc. write-throughd. cache bypassinganswer: c25. which business continuance solution will enable the minimum rto?a. using tape restore at a hot siteb. clustered production serversc. using a data vault to a host sited. using periodic replication at a hot siteanswer: b26. an application uses ten 9 gb devices. a pointer based replica of the application is required every 4 hours. each replica will be kept for 24 hours. the data changes by 10% every 4 hours. how many replica devices are required?a. 90b. 60c. 120d. 6answer: b27. what does san security architecture recommend?a. multiple integrated layers of securityb. single integrated solution for securityc. multiple isolated layers of securityd. multiple isolated solutions for securityanswer: d28. which nas solution is the easiest to deploy in an existing emc san environment?a. bridged nas with iscsi technologyb. gateway nas system solutionc. integrated nas system with iscsi technologyd. integrated nas system solutionanswer: b29. in the diagram, which zone(s) represent hard zone?a. zone 2b. zone 1 and 3c. zone 3d. zone 1answer: a30. what is one reason a company might choose to deploy nas?a. for array managed data securityb. for host managed storage volumesc. to obtain content addressed storaged. to support a heterogeneous operation environmentanswer: d31. what monitoring characteristic per you to assess the risk of failure of fc switch ports before the ports actually fail?a. performanceb. accessbilityc. capacityd. securityanswer: b32. consider a disk i/o system in which an i/o request arrives at a rate of 100 iops and the service time is 4 ms. what is the utilization?a. 80%b. 4%c. 10%d. 40%answer: d u = a rs33. a customer with a san environment is primarily concerned about cabling flexibility. for this customer, which zoning method should be used?a. mixed zoningb. port zoningc. hard zoningd. wwn zoninganswer: d34. an application uses ten 20 gb devices. a pointer based replica of the application is required. the replica will be kept for 24 hours. the data changes by 20% every 24 hours. how much storage should be allocated for thea. 40gbb. 200 gbc. 20 gbd. 4 gbanswer: a35. in the context of protecting the fc storage infrastructure, what is an example of infrastructure integrity?a. preventing node login to the fabric without proper authorizationb. implementing isns discovery domainsc. not permitting physical access to the nodesd. improving the fspf algorithm to determine to isolated nodesanswer: a36. what attribute other than individual identity or group membership can be used to restrict access in the context of information security?a. host network addressb. hba world wide namec. roled. shared passwordsanswer: c37. what is the requirement for native iscsi implementation?a. host with nic and array with fcip portb. host with iscsi hba and array with fc portc. host with toe card and array with iscsi portd. host with software iscsi initiator and array with fcip portanswer: c38. what does a cache dirty page indicate?a. data requested by host but not yet fetchedb. data read from disk but not accessed by the hostc. data that has changed but is not yet written to diskd. data that has changed and has been written to diskanswer: c39. what is the failure that raid technology guards against?a. switch failureb. disk failurec. host bus adapter failuresd. host failuresanswer: b40. which service is used by iscsi initiator to discover targets?a. internet storage name serviceb. storage internet name sevicec. domain name serviced. network information serviceanswer: a41. what is the function of fc-1 layer in the fibre channel protocol?a. interface mappingb. routing and flow controlc. transmission of raw bitsd. encoding and decodinganswer: d (p45)42. what is the operating environment for emc clariion?a. access logixb. enginuityc. flared. emc linuxanswer: c43. what is the operating systemd of celerra control station?a. data access at real timeb. centra starc. windows ced. linuxanswer: a (p86)44. to what does a redundant array of independent node architecture refer?a. technology independent object storage networkb. cluster storage and access node networkc. data independent storage and host networkd. location independent storage networkanswer: b45. which statement best applies to a fibre channel san?a. multi-purpose client-server networkb. dedicated storage networkc. global interconnectivity networkd. multi-protocol storage networkanswer: b46. which feature assures that the stored content has not been altered in the cas system?a. single instance storageb. content integrityc. content authenticityd. content securityanswer: b (p180)47. which protocol implementation is used in a fibre channel san?a. scsi over fcb. fc over scsic. fc over serial attached scsid. fc over iscsianswer: a48. what describes the sustained internal transfer rate of disk drives?a. it is the speed at which data moves from read/write head to platterb. it is the speed at which data moves from a track to internal bufferc. it is the advertised speed of the interfaced. it is the speed at which data moves from platter to read/write headanswer: b49. which is used as backup media in virtual tape library?a. optical disksb. tapesc. virtual tapesd. disksanswer: d50. what is an advantage of using disk over tape when selecting a backup destination device?a. better portabilityb. quicker restoresc. higher acquisition costd. better rpoanswer: b51. which management task eliminates single points of failure in a data center?a. capacityb. availabilityc. performanced. securityanswer: b52. which one of the following is not an example of storage virtualization?a. chs to lba addressingb. lun creationc. virtual machinesd. host based volume managementanswer: c53. what is the reserved lun pool in emc clariion snapview replication?a. luns that can hold cofw datab. luns that are reserved for use by a specific hostc. luns that can be used as hot sparesd. luns that are not assigned a raid typeanswer: a54. what should be considered when determining the optimal size of the log file in host based log shipping remote replication?a. size of the standby databaseb. size of the source databasec. frequency of log switchingd. frequency of accessing databaseanswer: c55. which protection strategy can be applied to the security zone containing switches and routers?a. implementing secured remote accessb. masking based on source fcidc. use two factor authentication for network accessd. using e port authentication for accessanswer: d56. which data center element organizes customer and product information?a. serverb. storage arrayc. operating systemd. dbmsanswer: a57. which mechanisms address threats to the application access domain by elevation of user privileges?a. access control to storage objects and access control lists(acls)b. access control to storage objects and storage access monitoringc. user authentication and information rights management(irm)d. user authentication and user authorizationanswer: a58. which emc control center component holds information about managed objects?a. agentb. storec. repositoryd. serveranswer: c59. what is the sequence of steps in nas i/o?1. storage array processes the request2. nas device converts file i/o to block i/o3. file i/o request by client4. nas device forwards the file to the clienta. 2-1-4-3b. 2-1-3-4c. 3-2-1-4d. 3-1-4-2answer: c60. what is the maximum payload in a fibre channel frame?a. 2136 bytesb. 2048 bytesc. 2148 bytesd. 2112 bytesanswer: d61. which remote replication solution has the lowest bandwidth requirement?a. array based synchronous replicationb. host-based lvm mirroringc. log shipping over ip networksd. asynchronous ordered writesanswer: c62. what is the process that writes physical address information to a disk?a. concatenatingb. formattingc. partitioningd. stripinganswer: b63. which data center element stores customer and product information when the server is connected to an array?a. applicationb. databasec. serverd. storage arrayanswer: b64. what does a cache dirty bit flag?a. changed data not yet written to diskb. changed data written to diskc. data read from disk but not accessed by the hostd. data requested by host but not yet fetchedanswer: a65. which component of emc controlcenter holds the information collected about the managed objects?a. agentb. repositoryc. serverd. storeanswer: b66. which remote replication solution has the highest bandwidth requirements?a. array based synchronous replicationb. asynchronous ordered writesc. log shipping over ip networksd. host based asynchronous lvm mirroringanswer: a67. which remote replication solution has the lowest bandwidth requirement?a. array based synchronous replicationb. asynchronous ordered writesc. host based lvm mirroringd. log shipping over ip networksanswer: d68. what are the five core elements of the data center infrastructure?a. applications, databases, jbod, networks, storage arraysb. applications, databases, servers/operating systems, das, nasc. applications, databases, servers/operating systems, networks, storage arraysd. applications, databases, servers/operating systems, san, jbodanswer: c69. data is being replicated from site a to site b using disk buffering to create extended distance consistent point in time copies every hour. in the event of a site failure at a, what is the maximum amount of data that will be missing at site b?a. 1 hourb. 2 hoursc. 3 hoursd. 4 hoursanswer: b70. what is the process that writes physical address information to a disk?a. concatenatingb. formattingc. partitioningd. stripinganswer: b71. the recovery point objective (rpo) of a company is 4 hours. which statement is true in the event of a disaster?a. must be able to restart their network within 4 hoursb. must be able to restart their servers within 4 hoursc. must be able to resume production within 4 hoursd. no more than 4 hours of production data can be lostanswer: d72. in san, if the primary concern is cabling flexibility, what method of zoning should be employed?a. hard zoningb. mixed zoningc. port zoningd. wwn zoninganswer: d73. which data center element stores customer and product information when the server is connected to an array?a. applicationb. databasec. serverd. storage arrayanswer: b74. what do you monitor as part of server performance?a. file system utilizationb. hba statusc. memory utilizationd. power supply statusanswer: c75. what best describes a fibre channel san?a. dedicated storage networkb. global interconnectivity networkc. multi-protocol storage networkd. multipurpose system networkanswer: a76. which aspect of monitoring will allow you to predict the possible failure of fc switch ports before the ports actually fail?a. capacityb. healthc. performanced. securityanswer: c77. what are the three key data center management activities that are interdependent?a. installation, configuration, problem solvingb. manageability, integrity, costc. provisioning, monitoring, reportingd. scalability, accessibility, securityanswer: c78. which celerra component is used to manage and configure the nas solution?a. control stationb. data moverc. disk array enclosured. storage processoranswer: a79. what is a reason for implementing single hba