Veeam Support Knowledge Base
The process cannot access the file because it is being used by another process

The process cannot access the file because it is being used by another process

KB ID:	1960
Product:	Veeam Backup & Replication
Published:	2014-11-19
Last Modified:	2024-12-03
Languages:	JP

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Antivirus Interference

Antivirus software can cause access issues similar to those documented in this article. Such interference often occurs when security software detects a Veeam process attempting to access a file and simultaneously locks the file for inspection, coinciding with the Veeam process's attempt to lock it. This interference is frequently short-lived, resulting in the antivirus software not being detected using the methods outlined in this article. However, it may be possible to track this interference using tools like Process Monitor to observe file activities within a specific folder. Ultimately, mitigating the impact of antivirus or security software boils down to creating AV exclusions to prevent such interference.

Challenge

A job or task fails with the error:

The process cannot access the file because it is being used by another process.

Indicating that a file is locked by another process/task. The console may indicate specifically what file is locked. Identification of the process that is locking the file(s) must take place.

Example:

Example of how this error appeared in all versions prior to Veeam Backup & Replication 12.

Starting in Veeam Backup & Replication 12, the error message will now include details about the locking process, when possible.

As shown, the improved error message includes the exact process name and process ID.

In this example, diskspd was used to intentionally lock the VBK file to cause this error to occur.

Solution

NAS Involvement

While a process on a NAS can lock a file, due to the way some NAS devices may restrict terminal access, it can be challenging to identify if any processes on the NAS itself are locking files. If a reboot of the NAS does not resolve the lock, it may be necessary to involve the storage vendor.

Windows File Lock Investigation

There are many ways to track down which process is locking a file; see below for examples.

The methods described in this article should be performed on the machine where the locked file is located.

Resource Monitor

Open Resource Monitor. (resmon.exe)
Switch the CPU tab.
Expand the Associated Handles section.
In the Search Handles field, enter the locked file's name, and press Enter
Review the Search Results

In this example, diskspd was used to intentionally lock the file to force the error to occur within Veeam Backup & Replication. While this is an unlikely real-world scenario, this is only meant to demonstrate utilizing the Associated Handles search function.

Process Explorer

Available from Microsoft: Process Explorer Download

Run Process Explorer with Administrator privileges by right-clicking on the executable and selecting 'Run as administrator,' this will ensure that all handles and locks will be visible.
In the menu bar, click Find and click Find Handle or DLL...

In the Process Explorer Search window that appears, enter the locked file's name.
Review the search results to determine which process is locking the file.

Linux File Lock Investigation

To determine file locks on a Linux repository, you can use various utilities. This section will focus on using lslocks, but keep in mind that there may be other distribution-specific tools and methods available. It's important to distinguish between locked and opened files, as a file can be locked without being actively opened. The lsof command, for example, only lists actively opened files.

lslocks — Displays a list of active file locks. (Requires util-linux package)
lsof — Displays a list of actively open files. Specifying a particular file will show active processes for that file.
```
lsof “/path/to/file”
```

Alternatively /proc/locks can be manually investigated using the following command:

sudo find -L /proc/*/fd -maxdepth 1 -print -exec readlink {} \;

Regardless of the method used, you must verify that the file is not actively being modified. File locks can come from various sources. For example, if a job is unexpectedly terminated due to a network drop, it is possible that the Veeam Agent finished but never received a terminate command. If the repository uses deduplication, the storage may have too aggressive of a profile active and is locking the file(s) as soon as Veeam releases a lock on them.

Once you have verified that the locked file is no longer being modified, it is safe to manually kill any process still maintaining a lock on the file. However, be cautious, as killing a process that is modifying a file may result in a corrupted file.

If this KB article did not resolve your issue or you need further assistance with Veeam software, please create a Veeam Support Case.

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The process cannot access the file because it is being used by another process

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Challenge

Solution

Windows File Lock Investigation

Resource Monitor

Process Explorer

Linux File Lock Investigation

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