Knowledge Base

The file is a temporary container that receives all pending write operations until the backup creation completes

This article applies to:

• Acronis Backup & Recovery 10 (All Editions)
• Acronis Backup & Recovery 11 (All Editions)

Description

If there is not enough storage space to create the temporary snapshot file, the backup operation will fail with an error message similar to the following one:

Not enough storage is available to process this command

For detailed description of the snapshot process, see SnapAPI. This article describes what this temporary file is and how to modify its size:

• Windows
• Linux

Windows

Once a snapshot is created, Acronis Backup & Recovery creates a temporary file in the %TEMP% folder of a user, under which a backup plan/policy is running. By default, the full path is:

• Windows 2000/XP/2003: \Documents and Settings\%username%\Local Settings\Temp
• Windows Vista/7/2008/2008 R2: \Users\%username%\AppData\Local\Temp

The name of the file is random, but is similar to acr74BD.tmp.

The size of this temporary file by default is exactly 20% of the free space of the partition where the temporary folder is.

This file is a container that has the snapshot image and receives all write operations from the system pending after the snapshot is created and before the backup creation completes.

This ensures that the created backup has the latest image of the system and that absolutely no piece of information is lost.

This temporary file is automatically deleted once the backup creation completes.

Changing the default relative size of the file

The default relative size is 20% of the free partition space.

By decreasing the default relative size you risk that the backup creation will fail when there is not enough space in the file to receive all the pending write operations. This is not recommended if you have a loaded system.

By increasing the default relative size you ensure that the backup creation will not fail due to lack of space in the file, but at the same time you risk that there will not be enough space for other applications that might need it.

To change the default size, do the following:

1. Open Windows Registry Editor (Start-Run -> regedit);
2. Browse to the following subkey:

   Acronis Backup & Recovery 11:

   • HKEY_LOCAL_MACHINE\SOFTWARE\Acronis\MMS\Configuration\Protection\Backup\SnapshotStorage

   Acronis Backup & Recovery 10:

   • Windows 32 bit: HKEY_LOCAL_MACHINE\SOFTWARE\Acronis\MMS\Configuration\Protection\Backup\SnapshotStorage
   • Windows 64 bit: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Acronis\MMS\Configuration\Protection\Backup\SnapshotStorage

   

   

3. Double-click on RelativeSize and set the Value data to the one you choose:

   

   In this example the relative size value is set to 70%.

4. Click OK.

Changing the storage path of the file

To change the default storage path, do the following:

1. Open Windows Registry Editor (Start-Run -> regedit);
2. Browse to the following subkey:

   Acronis Backup & Recovery 11:

   • HKEY_LOCAL_MACHINE\SOFTWARE\Acronis\MMS\Configuration\Protection\Backup\SnapshotStorage

   Acronis Backup & Recovery 10:

   • Windows 32 bit: HKEY_LOCAL_MACHINE\SOFTWARE\Acronis\MMS\Configuration\Protection\Backup\SnapshotStorage
   • Windows 64 bit: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Acronis\MMS\Configuration\Protection\Backup\SnapshotStorage

   

3. Double-click on StoragePath and in the Value data field provide the path where the temporary file should be created:

   

   In this example the storage path is set to C:\SnapTMP:

   

4. Click OK.
5. Recreate the backup plan.

(!) If HKEY_LOCAL_MACHINE\SOFTWARE\Acronis\MMS\Configuration\Protection\Backup\SnapshotStorage\StoragePath contains incorrect address or points to a folder that does not exist, the backup task will fail with error Failed to create temporary file. Make sure that you specify valid address and that the target folder exists.

Linux

Once a snapshot is created, Acronis product on Linux does not create a temporary file.

The temporary file is created only if the size of the snapshot data exceeds 12500 snapshotted filesystem blocks (it is 50 MB for a typical ext3 partitions with 4 KB block size).

The temporary file is created in the following default folder:

• /tmp

The name of the file is random, but is similar to acro_cache_XXXXXX.

If necessary, the size of this temporary file grows from zero until the size available on partition that keeps it.

Changing the storage path of the file

Temporary file location may be changed via setting the special environment variable ACRONIS_SNAPSHOT_TMP_DIR applied to process creating snapshot (typically it is BackupAndRecoveryService or TrueImageCmd). To set up this variable for all Acronis programs, it is recommended to add it into the /usr/lib/Acronis/system_libs/config file.

For example

WRAPPER=
ACRONIS_SNAPSHOT_TMP_DIR=/var/tmp

More information

See also:

• SnapAPI
• Installation of Acronis Products in Windows Creates Temporary Files in %TMP% on System Partition