This guide describes how to handle problems with Acronis Nonstop Backup operation, such as failure to start or errors during execution.

Acronis Nonstop Backup provides protection of your disks and files. It allows you to recover entire disks, individual files and their different versions.

This article is an overview of the problems that may be encountered during the Nonstop Backup operation. It also includes practical steps on correctly identifying and resolving them.

About Nonstop backup

Acronis Nonstop Backup is a feature that provides continuous protection of disks and files, allowing you to recover from disaster both entire volumes and individual files and even their versions.

At first run Acronis Nonstop Backup will create an initial backup of the data (files, folders, drives or partitions) selected for protection. Note: this may lower the machine's performance. This full backup is done only once.

Then a special Continuous Data Protection (CDP) driver is turned on. This CDP driver reads all requests to the protected items and copies these to its data buffer. Every 5 minutes these requests (which constitute file changes) are flushed (i.e. saved) to the Acronis Nonstop Backup storage. Thus, one time slice is created, while the CDP driver keeps reading the requests.

Since all the files were backed up in their entirety during the first run, every 5 minutes Acronis Nonstop Backup only saves the file changes, not the files themselves. In other words, Acronis Nonstop Backup "compares" the modified state of the file to its latest version from the archive and captures the difference.

Note, that if Acronis Nonstop Backup protects a non-system partition and no changes have occurred for 5 minutes since the last backup, the next scheduled backup will be skipped. Acronis Nonstop Backup will wait for a significant data change and will create a new incremental backup only when such change has been detected. In those cases, the actual time interval will exceed 5 minutes.

In addition, if, for instance, you are working in Word and do not use the "Save" operation for an hour, changes in the Word document will not be backed up every five minutes, because Acronis True Image 2014 checks file changes on the disk and not in the memory.

Known Issues

Acronis Nonstop Backup Pauses
True Image Home 2010: Nonstop Backup Fails to Start
Acronis True Image Home 2010: Acronis Nonstop Backup Errors Out with "Archive is not found" and "0x00D60027+0x00040007+0x0000FFF0"
Acronis True Image Home 2010: Acronis Nonstop Backup Errors Out with "Archive is not found" and "0x00D60027+0x00040011+0x0000FFF0"
Acronis True Image Home 2010: Nonstop Backup Fails with "0x00D60007+0x000003E9+0x001703EE"
Acronis True Image Home: Acronis Nonstop Backup Fails with "Unknown status"
Acronis True Image Home 2011: Nonstop Backup Errors Out with 0x00E40022+0x00000009
Acronis True Image Home 2011: Nonstop Backup Fails with "An error occurred during opening Acronis Nonstop Backup session"
Acronis True Image Home Errors Out with "An error occurred during starting Acronis Nonstop Backup session" and Error Code 0x00E4002E+0x00E40028+0x0000FFF0+0x80070651
Acronis True Image Home 2011 Errors Out with "An error occurred during starting Acronis Nonstop Backup session"
Acronis True Image Home 2012: Acronis Nonstop Backup Malfunctions After Upgrade to Acronis True Image Home 2012
Acronis True Image Home 2012: Nonstop Backup Fails with "An error occurred during opening Acronis Nonstop Backup session"
True Image 2013 by Acronis: Start of Nonstop Backup Fails with "Failed to Start Acronis Nonstop Backup Session"
Acronis True Image Home: Acronis Nonstop Backup Is Incompatible with Avira AntiVir
Acronis True Image Home 2011: "Cannot backup the folder to itself. Please choose a different destination for your nonstop backups." Error Message
Acronis True Image Home 2011:  Target Partition File System Is Not Supported by Nonstop Backup
Acronis True Image Home: Acronis Nonstop Backup Does Not Protect USB Drives
Acronis Nonstop Backup Does Not Support Network Shares or NAS
Acronis True Image Home 2011: Nonstop Backup Does Not Allow to Protect Dynamic Disks
Acronis True Image Home 2011 Nonstop Backup: "Cannot backup to non-NTFS partition" When Selecting NTFS Partition as Destination

Troubleshooting

Localize the issue and use available solutions:

Issues with backup-task creation

Prerequisites

1. Make sure that the selected backup-source is not an external USB HDD. Acronis Nonstop Backup cannot be used for protecting data stored on external hard drives.
2. If antivirus is installed in the system, add Acronis-related folders to exclusions of the antivirus.
3. Make sure that user specified for running Acronis True Image has Administrator privileges or is a member of the Backup Operators group(see Add a user account to a group).

Troubleshooting

1. Try to create a regular backup task (not Nonstop backup) with the same source and target as the Nonstop backup. Is the backup task created?
2. Try to select different source and target while creating a Nonstop backup task. Is the backup task created?
3. Collect diagnostic information described below.

First backup fails

Prerequisites

1. Select supported source and destination for the Nonstop Backup.
2. Verify that the Acronis Nonstop Backup Service (afcdpsrv.exe) is properly installed and running:
   

Troubleshooting

1. Check the Acronis Nonstop Backup operation logs for error messages - the majority of such messages contain useful information on the (probable) cause of failure.
2. See the Known issues section for a list of known and documented problems.
3. Be wary of messages about (meta)data corruption: in most cases they mean that program/service operation was abnormally terminated at some point and the archive/description got inconsistent.
4. Recreating the Nonstop Backup from scratch, in most cases, should fix the normal operational state of the service, however additional investigations are required to discover the original problem cause and to ensure that this corruption does not reoccur. Navigate to the Collect information section.

Nonstop Backup was working before, but fails to start/is constantly stopping now

Prerequisites

1. Check for any significant changes in the environment that may have affected the original setup (e.g. conflicting software was installed, for example, any backup software. There are antiviruses that have a backup function).
2. Confirm that both the source and destination are available and accessible (e.g. backup was set up to an external drive and it was disconnected or its letter has changed).
   To perform that, do the following:
   - Go to "Start" -> "Computer";
   - Enter the path of the backup source/destination to the Address bar and press Enter. The location should be successfully opened:
   

Troubleshooting

1. Verify that the Nonstop Backup archive is intact - issues may occur if 'Time Explorer Storage' folder or its contents are modified manually or by third-party software (AntiMalware, etc.);
2. All Acronis Nonstop Backup data is stored in the "Time Explorer Storage" folder which is hidden. It is located in the root of the partition that you select as the place for the Acronis Nonstop Backup storage. To be able to see hidden folders (including the "Time Explorer Storage" folder), follow these instructions;
3. Open the "Time Explorer Storage" folder and then open the folder which name looks like "C424670E-AD3E-4A09-9D0E-A098292CE224" or somethimg like that;
4. Check if the "cdp.metadata" is in the "Time Explorer Storage" folder. If the file has been moved, copy the file back into the "Time Explorer Storage" folder. It is impossible to start/recover Nonstop backup without "cdp.metadata" file;
   

2. Collect necessary diagnostic information if the suggested solutions did not resolve the issue or are not applicable.

Collect information

1. Collect System Report from the machine in question: see instruction for Acronis True Image 2016: Generating System Report, if this fails for any reason, you can use this AcronisInfo Utility. Check if "cdp.metadata" file is collected;
2. Process monitor log (PML) while reproducing the issue;
3. Separate log with error (if any);
4. Create a screenshot of the problem.