So if I exclude system backups work.  Include system and VSS fails.  if the volume is 500 MB or greater, VSS requires 320 MB of free space.  I have 640 free.  I have seen some mention about the limit VSS can use, but have not found how to expand that?

Any Ideas.

Your humble servant, Gramps

Hi Grey,

Something strange about that since disk management reports 62% free of 1.00 GB as 640 MB.  What OS is this and can we assume you have done all the usual checks for VSS problems and what is using drive space on that volume?

windows 7 sp1

vssadmin list writers is happy

who knows what is using the space in there :)

Log Name:      Application
Source:        VSS
Date:          7/28/2015 10:39:13 PM
Event ID:      8194
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      LYNN-HP.ADVANTAGE.local
Description:
Volume Shadow Copy Service error: Unexpected error querying for the IVssWriterCallback interface.  hr = 0x80070005, Access is denied.
. This is often caused by incorrect security settings in either the writer or requestor process.

Operation:
   Gathering Writer Data

Context:
   Writer Class Id: {e8132975-6f93-4464-a53e-1050253ae220}
   Writer Name: System Writer
   Writer Instance ID: {21cca02b-aec1-4111-8c39-a0abc453e02c}
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="VSS" />
    <EventID Qualifiers="0">8194</EventID>
    <Level>2</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2015-07-29T02:39:13.000000000Z" />
    <EventRecordID>2800</EventRecordID>
    <Channel>Application</Channel>
    <Computer>LYNN-HP.ADVANTAGE.local</Computer>
    <Security />
  </System>
  <EventData>
    <Data>0x80070005, Access is denied.
</Data>
    <Data>

Operation:
   Gathering Writer Data

Context:
   Writer Class Id: {e8132975-6f93-4464-a53e-1050253ae220}
   Writer Name: System Writer
   Writer Instance ID: {21cca02b-aec1-4111-8c39-a0abc453e02c}</Data>
    <Binary>2D20436F64653A20575254575254494330303030313236302D2043616C6C3A20575254575254494330303030313231342D205049443A202030303030313336382D205449443A202030303030353332302D20434D443A2020433A5C77696E646F77735C73797374656D33325C737663686F73742E657865202D6B204E6574776F726B53657276696365202020202020202D20557365723A204E616D653A204E5420415554484F524954595C4E4554574F524B20534552564943452C205349443A532D312D352D3230</Binary>
  </EventData>
</Event>

has Norton 360 disabled firewall and av no help

some hp something, may tro to kill it

It is looking like the problem was preinstalled HP Device Access Manager.  Have uninstalled that on one box so far and backups seem to be working.  Will follow back up later

Did 2 more boxes.  Remove the HP Device access manager and all is well.  Everything would backup except the system partition with it installed.