Cohesity COH-285 - Cohesity Certified Protection Professional – NetBackup Appliances

The correct answer is C because the failure is an authorization problem on the NetBackup client, not a basic network-connectivity failure. The job output explicitly states that nbumaster8 “is not an authorized server for host nbclient1,” followed by status 59: access to the client was not allowed. Cohesity NetBackup documentation maps status code 59 to “Access to the client was not allowed.” The controlling configuration is the client’s SERVER list. Cohesity states that the SERVER entry defines the list of NetBackup primary and media servers that can access the NetBackup client, and that media servers or other primary servers must be added for that client. Cohesity also explains that on UNIX servers and clients, the SERVER entries in bp.conf define the NetBackup servers that are allowed access, with additional entries identifying servers that can initiate scheduled backups. Therefore, the client rejected the backup request because the requesting server name was missing from the client’s server list or did not match the expected resolved name. References/topics: Status code 59, SERVER option for NetBackup clients, bp.conf, Host Properties > Clients > Servers, and NetBackup host-name authorization.

The irrelevant consideration is the file system folder depth. When selecting between NetBackup Accelerator and NetBackup FlashBackup for a file system containing millions of files, the key design factors are capacity, file-count/metadata handling, change processing, policy support, and file system/platform compatibility—not how deeply folders are nested. Cohesity documents that Accelerator performs an initial full backup and creates a track log, then identifies changed data by comparing track-log information against file-system information for each file; on NTFS/ReFS it can also use the Windows change journal. Cohesity also states that Accelerator track-log sizing is relative to file system size and number of backup files, with sizing formulas based on number of files and used disk space—not directory depth. FlashBackup is documented as combining raw-partition backup speed with individual file restore, and the FlashBackup/FlashBackup-Windows policy types are platform-specific, making the type of file system/client platform relevant. Storage capacity is also relevant because FlashBackup size reporting uses the mounted Windows disk volume or UNIX raw disk partition size. References/topics: Accelerator operation, track-log sizing, FlashBackup policy types, and large file-system backup planning.

The correct recovery options are recovering the MSDP catalog from an MSDP catalog backup and restoring the MSDP catalog from an MSDP catalog shadow copy. Cohesity documentation explains that the NetBackup Deduplication Manager automatically creates daily MSDP catalog shadow copies and transaction logs. If corruption is detected, the Deduplication Manager restores the catalog from the most recent shadow copy and replays the transaction log so the recovered catalog is current. Cohesity also states that administrators should protect the MSDP catalog with a dedicated MSDP catalog backup policy, because a NetBackup catalog backup does not include the MSDP catalog. The MSDP catalog backup is the second tier of protection and is used when shadow copies are unavailable or corrupt. The official recovery guidance identifies the two MSDP catalog recovery options as Restore from a shadow copy and Recover from a backup, specifically noting that a hardware problem can cause complete loss of the MSDP catalog and shadow copies. Options C and D are not the documented standard recovery choices for bringing the MSDP catalog online, and option E is incorrect because the NetBackup catalog backup excludes the MSDP catalog. References/topics: MSDP shadow catalog, MSDP catalog backup policy, Recovering the MSDP catalog, and drcontrol-based catalog protection.

The replication job starts when the force interval for small replication jobs is reached. NetBackup SLP settings control how Storage Lifecycle Policy jobs are maintained and executed for the selected primary server. Cohesity documentation identifies these as SLP settings used to customize how SLP jobs run. For AIR replication batching, the controlling parameter here is SLP.MIN_SIZE_PER_REPLICATION_JOB. Official NetBackup documentation defines it as the smallest batch size that can run as a single replication job and states that the job does not run until enough images accumulate to reach that size, or until the force interval for small replication jobs is reached. (veritas.com)

In this scenario, three backups of 5GB each create only 15GB of eligible replication data. That is below the configured 20GB threshold, so NetBackup does not start the replication job based on size. Because the backup window has closed and no additional backup images will arrive, the batch cannot reach 20GB. NetBackup therefore submits the small replication batch when the oldest image reaches the configured 60-minute force interval. The force interval is specifically designed to prevent NetBackup from waiting too long before submitting a small replication job. (veritas.com)

The correct action is to increase the Maximum I/O Streams for the MSDP disk pool. In NetBackup disk storage, the disk pool stream limit is the effective gate for concurrent read/write activity against that pool. Cohesity documentation identifies Limit I/O streams as the disk-pool property that controls read and write streams, and notes that if the limit is reached, NetBackup queues jobs until a volume becomes available. The storage-unit Maximum concurrent jobs setting controls how many jobs NetBackup sends to a disk storage unit, but Cohesity also states that this setting is not the only concurrency limiter and depends on disk-pool and media-server factors. NetBackup performance guidance is more explicit for this scenario: the disk pool Max I/O Streams value sets concurrent read/write operations, while the storage unit concurrent-jobs value addresses backup/restore jobs and does not control secondary operations such as duplications and replications; those are usually dictated by Max I/O Streams. Therefore, increasing storage-unit jobs or SLP priority does not guarantee that AIR replications can run while backups consume all available disk-pool streams. The correct tuning point is the disk pool’s Maximum I/O Streams.