SBS 2003 backup errors

I have been successfully backing up my SBS 2003 R2 server using the ntbackup configured by the wizard for the last year.  In the last few weeks the following errors have started occuring,  the c: drive is backed up but the e: and f: drives fail ( all drives are partitions on the 1 disk ).  LOG NUMBER 1 is a copy
of the report from 21st March.  I subsequently have installed service pack 2 and the latest updates and erased the tape media but am now getting similar errors although the e:\ drive appears to be now backing up but not f:\.  I am using a different tape each day so I've ruled the tapes out.  I also completed a manual backup of the e:\ drive successfully before I ran the service pack updates so I'm thinking the tape drive is   also okay. LOG NUMBER 2 is a copy of the latest backup log.  Aside from the fact that there actually errors I don't see why ntbackup reports that it backed up successfully when a few lines previously in the log it states " the operation did not complete successfully".  Many thanks in advance for your consideration  




LOG NUMBER 1


20/03/2008 23:00
-------------------------------
Date: 20/03/2008
Time: 23:00
User: SYSTEM
-------------------------------

Backup Runner started.
NTMS session started successfully.
EnumerateNtmsObject(NTMS_LIBRARY) succeeded.
Will enumerate on 3 media libraries found.
GetNtmsObjectInformation(NtmsLibraryInfo) succeeded.
GetNtmsObjectInformation(NtmsLibraryInfo) succeeded.
Found an enabled library.
InventoryNtmsLibrary(NtmsInventoryOmid) succeeded.
Identify Media completed
EnumerateNtmsObject(NTMS_PHYSICAL_MEDIA) succeeded.
Will enumerate on 1 media types found.
GetNtmsObjectInformation(NtmsPhysicalMediaInfo) succeeded.
GetNtmsObjectInformation(NtmsMediaTypeInfo) succeeded.
Found a tape media type in the library (4mm DDS).
Launching NTBackup: ntbackup.exe backup "@C:\Program Files\Microsoft Windows Small Business Server\Backup\Small Business Backup Script.bks" /d "SBS Backup created on 20/03/2008 at 23:00" /v:yes /r:no /rs:no /hc:on /m normal /j "Small Business Server Backup Job" /l:s /p "4mm DDS" /UM
NTBACKUP LOG FILE: C:\Documents and Settings\SBS Backup User\Local Settings\Application Data\Microsoft\Windows NT\NTBackup\data\backup07.log
=====================<BEGIN NTBACKUP LOG FILE>=====================
Backup Status
Operation: Backup
Active backup destination: 4mm DDS
Media name: "Media created 20/03/2008 at 23:00"

Volume shadow copy creation: Attempt 1.
Backup (via shadow copy) of "C: System"
Backup set #1 on media #1
Backup description: "SBS Backup created on 20/03/2008 at 23:00"
Media name: "Media created 20/03/2008 at 23:00"

Backup Type: Normal

Backup started on 20/03/2008 at 23:03.
Backup completed on 21/03/2008 at 02:38.
Directories: 5452
Files: 62424
Bytes: 13,733,250,907
Time:  3 hours,  34 minutes, and  47 seconds

Error: The device reported an error on a request to mount the media.
Error reported: Unknown error.
There may be a hardware or media problem.
Please check the system event log for relevant failures.

Error: E: is not a valid drive, or you do not have access.


Error: The device reported an error on a request to mount the media.
Error reported: Unknown error.
There may be a hardware or media problem.
Please check the system event log for relevant failures.

Error: F: is not a valid drive, or you do not have access.


Error: The device reported an error on a request to mount the media.
Error reported: Unknown error.
There may be a hardware or media problem.
Please check the system event log for relevant failures.

Error: SERVER01\Microsoft Information Store\First Storage Group is not a valid drive, or you do not have access.


Error: The device reported an error on a request to mount the media.
Error reported: Unknown error.
There may be a hardware or media problem.
Please check the system event log for relevant failures.

----------------------

The operation did not successfully complete.

----------------------

=======================<END NTBACKUP LOG FILE>=====================
NTBackup finished the backup with no errors.
Backup ended at 21 March 2008 02:39
Backup Runner finished.


LOG NUMBER 2
 


01/04/2008 23:00
-------------------------------
Date: 01/04/2008
Time: 23:00
User: SYSTEM
-------------------------------

Backup Runner started.
NTMS session started successfully.
EnumerateNtmsObject(NTMS_LIBRARY) succeeded.
Will enumerate on 3 media libraries found.
GetNtmsObjectInformation(NtmsLibraryInfo) succeeded.
GetNtmsObjectInformation(NtmsLibraryInfo) succeeded.
Found an enabled library.
InventoryNtmsLibrary(NtmsInventoryOmid) succeeded.
Identify Media completed
EnumerateNtmsObject(NTMS_PHYSICAL_MEDIA) succeeded.
Will enumerate on 1 media types found.
GetNtmsObjectInformation(NtmsPhysicalMediaInfo) succeeded.
GetNtmsObjectInformation(NtmsMediaTypeInfo) succeeded.
Found a tape media type in the library (4mm DDS).
Launching NTBackup: ntbackup.exe backup "@C:\Program Files\Microsoft Windows Small Business Server\Backup\Small Business Backup Script.bks" /d "SBS Backup created on 01/04/2008 at 23:00" /v:yes /r:no /rs:no /hc:on /m normal /j "Small Business Server Backup Job" /l:s /p "4mm DDS" /UM
NTBACKUP LOG FILE: C:\Documents and Settings\SBS Backup User\Local Settings\Application Data\Microsoft\Windows NT\NTBackup\data\backup01.log
=====================<BEGIN NTBACKUP LOG FILE>=====================
Backup Status
Operation: Backup
Active backup destination: 4mm DDS
Media name: "Media created 01/04/2008 at 23:00"

Volume shadow copy creation: Attempt 1.
Backup (via shadow copy) of "C: System"
Backup set #1 on media #1
Backup description: "SBS Backup created on 01/04/2008 at 23:00"
Media name: "Media created 01/04/2008 at 23:00"

Backup Type: Normal

Backup started on 01/04/2008 at 23:02.
Backup completed on 01/04/2008 at 23:53.
Directories: 4654
Files: 45911
Bytes: 11,828,911,828
Time:  50 minutes and  19 seconds
Backup (via shadow copy) of "E: Data"
Backup set #2 on media #1
Backup description: "SBS Backup created on 01/04/2008 at 23:00"
Media name: "Media created 01/04/2008 at 23:00"

Backup Type: Normal

Backup started on 01/04/2008 at 23:53.
Backup completed on 02/04/2008 at 00:32.
Directories: 1641
Files: 61976
Bytes: 6,086,063,457
Time:  39 minutes and  17 seconds

Error: The device reported an error on a request to mount the media.
Error reported: Unknown error.
There may be a hardware or media problem.
Please check the system event log for relevant failures.

Error: F: is not a valid drive, or you do not have access.


Error: The device reported an error on a request to mount the media.
Error reported: Unknown error.
There may be a hardware or media problem.
Please check the system event log for relevant failures.

Error: SERVER01\Microsoft Information Store\First Storage Group is not a valid drive, or you do not have access.


Error: The device reported an error on a request to mount the media.
Error reported: Unknown error.
There may be a hardware or media problem.
Please check the system event log for relevant failures.

----------------------

The operation did not successfully complete.

----------------------

=======================<END NTBACKUP LOG FILE>=====================
NTBackup finished the backup with no errors.
Backup ended at 02 April 2008 00:33
Backup Runner finished. Start Free Trial