Exchange GRT (Granular Restore Technology) Backups fail when backing up to remote B2D (Backup to Disk) on a NAS (Network Attached Storage) device.
Exchange GRT backup fails with error - 1022 There is a disk IO error when backing up to remote B2D on NAS box (For e.g. Western Digital NAS box)
0xe00084af - The directory or file was not found, or could not be accessed.
Backup- \\Exchange Server Name\Microsoft Information Store\First Storage Group
Database was not found, or could not be accessed.
Beremote debug log on Backup Exec server:
 02/24/09 16:23:53 JetExternalRestore(2) - ERROR::RC = -1022 - -1022 There is a disk IO error.
 02/24/09 16:23:54 Using EDB Provider for Browse/Backup.
 02/24/09 16:23:54 Logon: m_lpMAPISession->Logon returned 80004005
 02/24/09 16:23:54 OPEN DATABASE FAILED: -1022 There is a disk IO error.
1. Run LiveUpdate and install the latest hotfixes.
Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and workstation be made prior to making any registry changes.
2. Add the following registry key on the Backup Exec media server:
Key : HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VirtFile
Value: VFF Extended Timeout
The Maximum Decimal value is 600 seconds.
Start out at 240 seconds at first. If error still occurs then 480, before going to 600.
3. Restart the "Backup Exec Remote Agent for Windows Systems " service for the change to take effect.