Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > alt.comp.os.windows-11 > #17812

Re: MS Shadow Copy service

Show all headers | View raw

On Mon, 3/17/2025 5:27 PM, Newyana2 wrote:
> On 3/17/2025 3:32 PM, Paul wrote:
>> On Mon, 3/17/2025 12:45 PM, Frank Slootweg wrote:
>>> Newyana2 <newyana@invalid.nospam> wrote:
>>> [...]
>>>
>>> $DRIFT ON
>>>
>>>>     I've had Volume Shadow Copy disabled for as long as I
>>>> can remember. Disk image backup is much better than
>>>> system restore. ...
>>>
>>>    Volume Shadow Copy is not only used for System Restore, but also by
>>> any decent backup program, including disk/partition backup programs.
>>>
>>>    If a disk/partition backup program does not use Volume Shadow Copy to
>>> make a snapshot of the disk/partitions, it can not do make an on-line
>>> backup, nor do a verify after the backup.
>>>
>>> $DRIFT OFF
>>>
>>
>> A backup cannot back up open file handles, without the shadow service.
>> (Most) open file handles, will be handled properly using VSS. Only the file
>> handles that won't quiesce will not be handled. Whether you have
>> VSS or not, pagefile.sys cannot be backed up (well, as you would expect --
>> nobody really wants their pagefile.sys backed up!).
>>
> 
>     Does nobody know about real disk image backup? Incremental backup
> is only local. It's like a faux RAID array, and only as good as the
> machine it's on. It also takes up a lot of room.
> 
>   There seems to be confusion, starting some years ago with overpriced
> "disk imaging" software that merely does incremental backup from within
> Windows. People thought that was disk imaging and paid through the nose
> for things like Acronis because it did a lot of hand holding. That is not disk
> image backup. Disk image backup is backing up a partition or disk to
> a compressed file(s) that can later be restored. It is not and cannot be
> done from within Windows. Even Frank the grouch seems to not know
> the difference.

Sure it can be. You use VSS, "freeze" the state of the C: partition,
then do cluster by cluster recording. Compression is optional while
this is going on. Most runtime compressors are light-weight, and
not a big win. You can do a backup .img file, and then compress it
to .img.7z if you want, for long term storage. I generally tend to
compress backup files, if it looks like the chances of using them
or needing them, is slim.

When they are not Incremental or Differential, they are called "Full".
That means the .mring file (or whatever proprietary format that is used),
is a complete recording of the disk drive. MBR, boot track, ESP, C: partition,
System Reserved, Recovery Partition, GPT tables. Every bit of the non-white
space is recorded in a Full.

    Full                                                              (what I use, no screwing around)

    Full + Differential1, Full + Differential2, Full + Differential3  (three restores possible, using an orig. Full)

    Full, Full + Incremental1, Full + Incremental1 + Incremental2    (restores built from Full, plus sigma(incrementalN)

Only the clusters of a few files, are missed. These would be on files
which had open file handles, and would not temporarily quiesce so
they could be part of the "frozen" C: . Other partitions are
frozen too, except the files on "data" drives are not nearly as
badly behaved as the files on the C: drive. There usually isn't a
problem (or notes) for backup of "data" drives.

The System Volume Information can contain shadows placed
there for other purposes, such as the Restore Points for
System Protection. I don't think a shadow can be "recorded",
so those might not be in the image created.

A lot of the image formats, can be mounted. They can be
mounted while the real item is running. I can be
looking at partition C: at the same time as a I mount
the .mrimg containing C: and re-labeled as being K: .
Then, if I want, I can compare which files are captured
in K: , compared to the C: it came from.

One of the first mountable formats, might have been the
old Ghost. Acronis may have come after that. But the others
who wanted to be competitive, also have mounters. These
mounters allow individual files to be copied, without
doing a full restore to a spare hard drive.

   Paul

Back to alt.comp.os.windows-11 | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-16 17:02 -0400
  Re: MS Shadow Copy service User One <noreply@invalid.com> - 2025-03-16 22:03 +0000
    Re: MS Shadow Copy service Stan Brown <the_stan_brown@fastmail.fm> - 2025-03-16 20:42 -0700
    Re: MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-29 00:50 -0400
      Re: MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-29 01:38 -0400
  Re: MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-16 21:49 -0400
    Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-17 00:46 -0400
      Re: MS Shadow Copy service "Carlos E.R." <robin_listas@es.invalid> - 2025-03-17 13:16 +0100
        Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-17 11:25 -0400
          Re: MS Shadow Copy service "Carlos E.R." <robin_listas@es.invalid> - 2025-03-17 19:50 +0100
            Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-17 15:27 -0400
              Re: MS Shadow Copy service "Carlos E.R." <robin_listas@es.invalid> - 2025-03-17 21:34 +0100
                Re: MS Shadow Copy service Frank Slootweg <this@ddress.is.invalid> - 2025-03-18 14:45 +0000
                Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-18 20:13 -0400
    Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-17 01:07 -0400
      Re: MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-27 01:00 -0400
        Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-27 02:51 -0400
  Re: MS Shadow Copy service Newyana2 <newyana@invalid.nospam> - 2025-03-17 08:41 -0400
    Re: MS Shadow Copy service Frank Slootweg <this@ddress.is.invalid> - 2025-03-17 16:45 +0000
      Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-17 15:32 -0400
        Re: MS Shadow Copy service Newyana2 <newyana@invalid.nospam> - 2025-03-17 17:27 -0400
          Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-17 18:16 -0400
          Re: MS Shadow Copy service Frank Slootweg <this@ddress.is.invalid> - 2025-03-18 13:49 +0000
  Re: MS Shadow Copy service Frank Slootweg <this@ddress.is.invalid> - 2025-03-17 16:36 +0000
    Re: MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-27 01:05 -0400
      Re: MS Shadow Copy service Char Jackson <none@none.invalid> - 2025-03-28 00:27 -0500
        Re: MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-28 12:17 -0400
  Re: MS Shadow Copy service ...w¡ñ§±¤ñ  <winstonmvp@gmail.com> - 2025-03-17 10:44 -0700
    Re: MS Shadow Copy service Newyana2 <newyana@invalid.nospam> - 2025-03-17 17:28 -0400
      Re: MS Shadow Copy service Paul <nospam@needed.invalid> - 2025-03-17 18:50 -0400
      Re: MS Shadow Copy service ...w¡ñ§±¤ñ  <winstonmvp@gmail.com> - 2025-03-20 11:52 -0700
        Re: MS Shadow Copy service micky <NONONOmisc07@fmguy.com> - 2025-03-27 01:09 -0400

csiph-web