Nutanix Files, part of Nutanix Unified Storage (NUS), provides CIFS (SMB) shares that can be accessed by Windows clients. RoboCopy (Robust File Copy) is a Windows command-line tool commonly used to copy files to SMB shares, such as those provided by Nutanix Files. The administrator is copying large files to a Files share using RoboCopy, but the operation was interrupted due to a network bandwidth issue. The goal is to resume the interrupted copy operation without restarting from scratch.
Analysis of Options:
Option A (robocopy with the /c option): Incorrect. The /c option is not a valid RoboCopy option. RoboCopy options typically start with a forward slash (e.g., /z, /s), and there is no /c option for resuming interrupted copies.
Option B (robocopy with the /s option): Incorrect. The /s option in RoboCopy copies subdirectories (excluding empty ones) but does not provide functionality to resume interrupted copy operations. It is used to define the scope of the copy, not to handle interruptions.
Option C (robocopy with the /z option): Correct. The /z option in RoboCopy enables “restartable mode,” which allows the tool to resume a copy operation from where it left off if it is interrupted (e.g., due to a network issue). This mode is specifically designed for copying large files over unreliable networks, as it checkpoints the progress and can pick up where it stopped, ensuring the copy operation completes without restarting from the beginning.
Option D (robocopy with the /r option): Incorrect. The /r option in RoboCopy specifies the number of retries for failed copies (e.g., /r:3 retries 3 times). While this can help with transient errors, it does not resume an interrupted copy operation from the point of interruption—it retries the entire file copy, which is inefficient for large files.
Why Option C?
The /z option in RoboCopy enables restartable mode, which is ideal for copying large files to a Nutanix Files share over a network that may experience interruptions. This option ensures that if the copy operation is interrupted (e.g., due to a network bandwidth issue), RoboCopy can resume from the point of interruption, minimizing data retransmission and ensuring efficient completion of the copy.
Exact Extract from Microsoft Documentation (RoboCopy):
From the Microsoft RoboCopy Documentation (available on Microsoft Docs):
“/z : Copies files in restartable mode. In restartable mode, if a file copy is interrupted, RoboCopy can resume the copy operation from where it left off, which is particularly useful for large files or unreliable networks.”
Additional Notes:
Since RoboCopy is a Microsoft tool interacting with Nutanix Files SMB shares, the behavior of RoboCopy options is standard and not specific to Nutanix. However, Nutanix documentation recommends using tools like RoboCopy with appropriate options (e.g., /z) for reliable data migration to Files shares.
Nutanix Files supports SMB features like Durable File Handles (as noted in Question 19), which complement tools like RoboCopy by maintaining session state during brief network interruptions, but the /z option directly addresses resuming the copy operation itself.
[:, Microsoft RoboCopy Documentation, Section: “RoboCopy Command-Line Options” (Microsoft Docs)., Nutanix Files Administration Guide, Version 4.0, Section: “Data Migration to Nutanix Files” (Nutanix Portal)., , ]
