Type : Error
Event : 6794
Source : Enterprise Vault
Category : Migrator Server
Computer : EVServer.domain.com
Description: Error restoring Saveset during export operation.
Job Id: Exp3_20130515102338
Vault Name: EVArchive
Vault Id: 1015R97478F7A1A4DBE6A78B3F471535C1110000evsite
Saveset Id: 201301234566669~201305060154890000~Z~50548DE77019784C9344D98FFDEBE121
Reference: RS/SA/RI
V-437-6794
Type : Error
Event : 6609
Source : Enterprise Vault
Category : Migrator Server
User : N/A
Computer : EVServer.domain.com
Description: PST file access error occurred
PST file: C:\TEMP\Exported\EVServer_Export_0001.pst
Account: Domain\vsaaccount
Reference: SPA/OMS
V-437-6609
Type : Warning
Event : 6769
Source : Enterprise Vault
Category : Migrator Server
Computer : EVServer.domain.com
Description: Export Archive Report
Export status: Incomplete
Processing aborted due to an unrecoverable error.
Job Id: Exp3_20130515102338
Archive Name: EVServer
Vault Id: 1015R97478F7A1A4DBE6A78B3F471535C1110000evsite
Target PST file location: C:\TEMP\Exported\EVServer_Export_0001.pst
Number of PST files: 0
Number of items restored: 0
Number of items unable to be restored: 0
Age range filter: 05/May/2013 12:59 - 09/May/2013 12:59
Retention category filter:
Elapsed Export Time: 00:23:59 (hours:minutes:seconds)
V-437-6769
The behavior in question may occur when the Enterprise Vault Server Cache location is either full or low on drive space.
Check the Maximum Cache Size within the VAC, see screen shot below:

Then check the size of the Cache folder to see if it is near the limit.
Note: The below mentioned are also utilized by the cache location:
Adjust size of cache location accordingly based on Maximum Cache Size limit.
Follow these steps to set a cache location:
Note: The minimum size of the server Cache location is 10 GB and the default size is 20 GB.