discarding redundant backup images

[userX]

Recently I found it necessary to restore a backup image earlier than the most recent image because the informational changes in the last backup were undesirable. Under these circumstances, when I restore an image next to the last one, I think it is safe to discard the last one if I want. Is that not so?

Also, supposing I have a base backup image of the whole disk, together with several incremental backups, if I were then to create a new differential backup using this same original whole disk image, I think it would be safe to discard the multiple incremental backups made before the last differential one because I could now use the last one and the original whole disk image as a complete set.

The interim increments were useful and efficient to make for a period of time, but after a while I can bypass them completely with a new differential based off the same original. Is that not so?

[TeraByte Support]

you can restore from whatever point you want within the chain.

"userX" wrote in message news:[email protected]...

Recently I found it necessary to restore a backup image earlier than the
most recent image because the informational changes in the last backup were
undesirable. Under these circumstances, when I restore an image next to the
last one, I think it is safe to discard the last one if I want. Is that not
so?

Also, supposing I have a base backup image of the whole disk, together with
several incremental backups, if I were then to create a new differential
backup using this same original whole disk image, I think it would be safe
to discard the multiple incremental backups made before the last
differential one because I could now use the last one and the original whole
disk image as a complete set.

The interim increments were useful and efficient to make for a period of
time, but after a while I can bypass them completely with a new differential
based off the same original. Is that not so?


[TAC109]

On Mon, 18 Mar 2013 15:59:50 PDT, userX wrote:

>Recently I found it necessary to restore a backup image earlier than the most recent image because the informational changes in the last backup were undesirable. Under these circumstances, when I restore an image next to the last one, I think it is safe to discard the last one if I want. Is that not so?
>
>Also, supposing I have a base backup image of the whole disk, together with several incremental backups, if I were then to create a new differential backup using this same original whole disk image, I think it would be safe to discard the multiple incremental backups made before the last differential one because I could now use the last one and the original whole disk image as a complete set.
>
>The interim increments were useful and efficient to make for a period of time, but after a while I can bypass them completely with a new differential based off the same original. Is that not so?
>
In my opinion there are several aspects to restoring from images.

A most important, but often overlooked consideration is the 'time
machine' effect.

You have an edited file which has lost some data. Using your images,
you can go back in time and restore a previous version of this file
which contains the data lost. The more often you take images, the more
file grained can be the time slots available from which to obtain this
previous file version.

For this reason I'm against eliminating or combining old images. The
Differentials or Incrementals don't take up much room and are
available for the situation described above. Instead, I keep all old
images on a removable HD until the space is needed to create the new
images.

[mjnelson99]

After seeing your questions, I am glad I only do full images.

I guess if I had a drive with 150 GB of "stuff" I might feel
differently.

I am currently using SD cards for my images. My Win 7 X64
takes a 16 gb card.

My card reader works from either IFD or IFL running on SD
cards since the program there is necessary to create or
restore the image. You could also boot from CD or DVD and
still image/restore to/from SD.
Mary

On 3/18/2013 4:59 PM, userX wrote:
> Recently I found it necessary to restore a backup image earlier than the most recent image because the informational changes in the last backup were undesirable. Under these circumstances, when I restore an image next to the last one, I think it is safe to discard the last one if I want. Is that not so?
>
> Also, supposing I have a base backup image of the whole disk, together with several incremental backups, if I were then to create a new differential backup using this same original whole disk image, I think it would be safe to discard the multiple incremental backups made before the last differential one because I could now use the last one and the original whole disk image as a complete set.
>
> The interim increments were useful and efficient to make for a period of time, but after a while I can bypass them completely with a new differential based off the same original. Is that not so?
>
> 
>
>
>

[DrTeeth]

On Mon, 18 Mar 2013 15:59:50 PDT, just as I was about to take a herb,
userX disturbed my reverie and wrote:

>>he interim increments were useful and efficient to make for a period of time, but after a while I can bypass them completely with a new differential based off the same original. Is that not so?<<

Yes!
--

Cheers

DrT
______________________________
We may not be able to prevent the stormy times in
our lives; but we can always choose whether or not
to dance in the puddles (Jewish proverb).

[userX]

mjnelson99 wrote:
> After seeing your questions, I am glad I only do full images.
>
> I guess if I had a drive with 150 GB of "stuff" I might feel
> differently.
>
> I am currently using SD cards for my images. My Win 7 X64
> takes a 16 gb card.
>

What type of file system is the SD card made of? I am inclined to think that Win7 x64 alone would occupy 16 GB. Is that not so?

[mjnelson99]

I went straight to a 16 GB card formatted ntfs on new 64 bit
computer so am not sure if an 8 would have worked. My guess
was it would not have been large enough.

I also have two 32 GB cards I can put 2 images on. With this
size SD card some card readers will not work. I have had no
trouble with the 16 GB cards so far.

I do know on my old laptop with 32 bit Win 7 Home Premium an
8 gb card can be used for C:

On 3/21/2013 12:28 PM, userX wrote:
> mjnelson99 wrote:
>> After seeing your questions, I am glad I only do full images.
>>
>> I guess if I had a drive with 150 GB of "stuff" I might feel
>> differently.
>>
>> I am currently using SD cards for my images. My Win 7 X64
>> takes a 16 gb card.
>>
>
> What type of file system is the SD card made of? I am inclined to think

that Win7 x64 alone would occupy 16 GB. Is that not so?
>
>

[Brian K]

Mary,

I've noticed you are keen on SD cards. Why do you prefer them to USB HDs? Just curious.

[DrTeeth]

Brian K wrote:
> Mary,
>
> I've noticed you are keen on SD cards. Why do you prefer them to USB HDs?
> Just curious.

If my backups were as tiny as Mary's. I'd use memory cards too. My backups take up so muc space, that I have one internal 2TB disk and one external (in USB3 housing) to cope. I mirror the internal to the external.

DrT

[mjnelson99]

They are small, portable, and separate from each other.
If one goes bad, I still have others.

I also image to the D partition more frequently than to SD.

If you need more than 32 GB an external HD would probably
work better for you.

There are now 64 GB SD cards that probably cannot be used
with standard reader/writers.
Mary

On 3/21/2013 8:10 PM, Brian K wrote:
> Mary,
>
> I've noticed you are keen on SD cards. Why do you prefer them to USB HDs? Just curious.
>
>