Differential Backups

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Ed Smith
Posts: 133
Joined: Thu Sep 01, 2011 6:14 pm

Differential Backups

Post by Ed Smith »

I have always done full backups only but tried a full and then a few days
later made a differential. I tried a restore just to see how it worked and
it was fine. I pointed the differential to the full.

My question is if you have a couple differentials and only one full, do you
always use just the last differential and point it to the full or use both
differentials ?

Thank You,
Ed.

TeraByte Support(PP)
Posts: 1644
Joined: Fri Aug 12, 2011 12:51 am

Re: Differential Backups

Post by TeraByte Support(PP) »

You would restore whichever differential you wanted (a single restore operation). If the full and differential(s) are in the same folder it should find the full automatically when you select the differential to restore.
Ed Smith
Posts: 133
Joined: Thu Sep 01, 2011 6:14 pm

Re: Differential Backups

Post by Ed Smith »

Thank You for the reply. I have them in separate folders and will now have
them in the same folder.

Ed.

"TeraByte Support (PP)" wrote in message news:15037@public.image...

You would restore whichever differential you wanted (a single restore
operation). If the full and differential(s) are in the same folder it should
find the full automatically when you select the differential to restore.

Bob Coleman
Posts: 785
Joined: Fri Aug 12, 2011 5:58 pm

Re: Differential Backups

Post by Bob Coleman »

Ed Smith wrote:
> I pointed the differential to the full.

I don't know what that means, but to give an example, let's say you create a full backup on Day 1. Then on Day 3, you create a changes only (differential) using the full from Day 1 as the base. On Day 5, you again create a differential using the full from Day 1 as the base.

You now have three files the full and the two differentials. When, you want to restore, you pick any one of the three as the thing to restore from.

If you pick the full, the result will be as the backed up disk existed when it was backed up on Day 1.

If you pick the differential created on Day 3, the result will be as the backed up disk as existed when it was backed up on Day 3.

If you pick the differential created on Day 5, the result will be as the backed up disk existed when it was backed up when it was backed up on Day 5.
Ed Smith
Posts: 133
Joined: Thu Sep 01, 2011 6:14 pm

Re: Differential Backups

Post by Ed Smith »

OK now I fully understand it and will have no problems.

Why I said I pointed my differential to the full backup was because I had
the differential and the full backup each in different folders. I will now
put the full and the differential in the same folder as when TBI replied,
they said this way the differential will find the full.

Thanks again everyone,
Ed.

"Bob Coleman" wrote in message news:15039@public.image...

Ed Smith wrote:
> I pointed the differential to the full.

I don't know what that means, but to give an example, let's say you create a
full backup on Day 1. Then on Day 3, you create a changes only
(differential) using the full from Day 1 as the base. On Day 5, you again
create a differential using the full from Day 1 as the base.

You now have three files the full and the two differentials. When, you want
to restore, you pick any one of the three as the thing to restore from.

If you pick the full, the result will be as the backed up disk existed when
it was backed up on Day 1.

If you pick the differential created on Day 3, the result will be as the
backed up disk as existed when it was backed up on Day 3.

If you pick the differential created on Day 5, the result will be as the
backed up disk existed when it was backed up when it was backed up on Day
5.

DrTeeth
Posts: 1289
Joined: Fri Aug 12, 2011 6:58 pm

Re: Differential Backups

Post by DrTeeth »

On Mon, 4 Jun 2018 14:05:43 EDT, just as I was about to take a herb,
"Ed" disturbed my reverie and wrote:

>Why I said I pointed my differential to the full backup was because I had
>the differential and the full backup each in different folders. I will now
>put the full and the differential in the same folder as when TBI replied,
>they said this way the differential will find the full.

My full backup is in a different folder to my
differentials/incrementals. Once I have pointed at the full backup, it
is remembered for subsequent backup runs. I use incrementals.
--
Cheers,

DrT

"If you want to find out what is wrong
with democracy, spend five minutes with
the average voter." - Winston Churchill
Bob Coleman
Posts: 785
Joined: Fri Aug 12, 2011 5:58 pm

Re: Differential Backups

Post by Bob Coleman »

DrTeeth wrote:

> My full backup is in a different folder to my
> differentials/incrementals. Once I have pointed at the full backup, it
> is remembered for subsequent backup runs. I use incrementals.

That's interesting, but the previous point was about finding the necessary files when restoring, I think.
DrTeeth
Posts: 1289
Joined: Fri Aug 12, 2011 6:58 pm

Re: Differential Backups

Post by DrTeeth »

On Tue, 5 Jun 2018 14:06:21 EDT, just as I was about to take a herb,
Bob Coleman disturbed my reverie and wrote:

>That's interesting, but the previous point was about finding the necessary files when restoring, I think.

Just been trough a test restore and was able to just click through.
The only file I have to select was the incremental I wanted to use.
The full was automatically filled in.
--
Cheers,

DrT

"If you want to find out what is wrong
with democracy, spend five minutes with
the average voter." - Winston Churchill
Bob Coleman
Posts: 785
Joined: Fri Aug 12, 2011 5:58 pm

Re: Differential Backups

Post by Bob Coleman »

DrTeeth wrote:
> On Tue, 5 Jun 2018 14:06:21 EDT, just as I was about to take a herb,
> Bob Coleman disturbed my reverie and wrote:
>
> Just been trough a test restore and was able to just click through.
> The only file I have to select was the incremental I wanted to use.
> The full was automatically filled in.
> --
Filled in where? I'd expect to only select an incremental, but I wouldn't expect to see the identification of the full anywhere.
DrTeeth
Posts: 1289
Joined: Fri Aug 12, 2011 6:58 pm

Re: Differential Backups

Post by DrTeeth »

On Wed, 6 Jun 2018 15:00:21 EDT, just as I was about to take a herb,
Bob Coleman disturbed my reverie and wrote:

>Filled in where? I'd expect to only select an incremental, but I wouldn't expect to see the identification of the full anywhere.

*Only* because my full is not in the same folder as the incrementals,
after selecting the incremental to use, the next window is an
opportunity to select where the next backup file is located. I click
through and the "select next backup file needed" is already filled in.
--
Cheers,

DrT

"If you want to find out what is wrong
with democracy, spend five minutes with
the average voter." - Winston Churchill
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