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Re: "Device or resource busy" during read (rsync)


Wow, thanks so much to both of you! This is a HUGE help.   I really 
appreciate your time.

Take care,
Rich

On 12/23/2013 03:36 AM, Corinna Vinschen wrote:
> On Dec 22 21:55, Mikhail Usenko wrote:
>> On Sun, 22 Dec 2013 00:02:10 +0000
>> Winkel, Richard J. <...> wrote:
>>
>>> I have a hard time believing this is an unusual question but I swear
>>> I've been googling everywhere without an answer!  :)
>>> I'm using rsync (under cygwin) to backup windows servers to a linux box
>>> and it's working wonderfully, except that if a file is open rsync can't
>>> access it even for reading.   I know some windows-based backup programs
>>> don't have the problem so I'm hoping there's some way to avoid it in
>>> cygwin.  I've looked at the cygwin mount options but don't see anything
>>> obvious.  Is there a way around it?
>> Hello, Richard
>> You need to use VSS which stands for 'Volume Shadow copy Service' (or  'Volume Snapshot Service') on Windows. It is based on copy-on-write technology below the NTFS level and is used by Windows to make backups of the running system including of opened and locked files. (Also VSS utilizes a number of 'writers' that helps to make a consistent backup of opened database files for instance.) The shadow copy may be created by using different userspace tools:
>> * vshadow.exe (http://msdn.microsoft.com/en-us/library/bb530725(VS.85).aspx)
>> * vssadmin.exe (on the server OSes)
>> * wmic.exe
>> * by calling COM WMI objects from windows script host (http://support.microsoft.com/kb/188135) - VBA or JS scripts or from Windows PowerShell scripts.
>>
>> The easiest way to access the created shadow snapshot:
>>   http://blogs.msdn.com/b/adioltean/archive/2008/02/28/a-simple-way-to-access-shadow-copies-in-vista.aspx
> You can access the shadow copies in Cygwin via /proc/sys:
>
>    $ cd /proc/sys/Device
>    $ ls -l HarddiskVolumeShadowCopy*
>    lr--r--r-- 1 Administrators SYSTEM      0 Dec 23 10:32 HarddiskVolumeShadowCopy{0f7ef985-69b8-11e3-8264-ccdf67e6642d} -> /proc/sys/Device/HarddiskVolumeShadowCopy2
>    brwxrwx--x 1 Administrators SYSTEM 0, 250 Dec 23 10:32 HarddiskVolumeShadowCopy2
>    $ cd HarddiskVolumeShadowCopy2/
>
> Note the trailing slash in the last cd command!  It's required due to
> the dualism of the HarddiskVolumeShadowCopy2 entry, being a device *and*
> the root dir of a drive.  ANyway, after this, you can access the shadow
> copy just like your normal drive:
>
>    $ ls
>    $Recycle.Bin            hiberfil.sys         swapfile.sys
>    bootmgr                 pagefile.sys         Symbols
>    BOOTNXT                 PerfLogs             System Volume Information
>    Config.Msi              Program Files        Users
>    cygwin                  Program Files (x86)  Windows
>    cygwin64                ProgramData
>    Documents and Settings
>
>> Then rsync can be used to copy files from the shadow snapshot after which the snapshot can be deleted.
> Right.
>
>
> Corinna
>

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