strange backup problem using Acronis True Image Home 2011

cccc · 01-28-2012, 04:11 PM

hi

I'm using Acronis True Image Home 2011 to backup my Debian machines and have a really strange problem.
I've 1,1 GB Squeeze (EXT4) *.tib image, if I restore it from NAS and make some changes like online updates, change desktop etc.
and try to backup into NAS again using Acronis, then the image file increases to more than 3GB!
Even if I delete lot of files and the image file should be lower.
I didn't have these problems with EXT3.
This happens quite often and cannot find any solution.

Doc CPU · 01-28-2012, 04:43 PM

Hi there,

Quote:

Originally Posted by cccc

I'm using Acronis True Image Home 2011 ...

so am I, for my Windows (2000 and XP) and Linux machines (Ubuntu and Mint).

Quote:

Originally Posted by cccc

I've 1,1 GB Squeeze (EXT4) *.tib image, if I restore it from NAS and make some changes like online updates, change desktop etc. and try to backup into NAS again using Acronis, then the image file increases to more than 3GB!

That sounds weird, but I don't fully understand what you really do, and I've never had a problem like that. Could you explain that a bit more clearly?

[X] Doc CPU

cccc · 01-28-2012, 06:23 PM

Quote:

Originally Posted by Doc CPU

That sounds weird, but I don't fully understand what you really do, and I've never had a problem like that. Could you explain that a bit more clearly?

[X] Doc CPU

I've Squeeze setuped on a PC.
I've done a backup of the whole hard disk using Acronis over LAN to a NAS.
*tib image file is 1,1 GB.
I've restored it from NAS on the same PC.
I've done online updates and I've created an image file with Acronis again.
Now is the *tib image file larger than 3GB.

BTW I've already tried with different NAS and LAN, but still the same problem.

Doc CPU · 01-29-2012, 07:22 AM

Hi there,

Quote:

Originally Posted by cccc

I've Squeeze setuped on a PC.
I've done a backup of the whole hard disk using Acronis over LAN to a NAS.
*tib image file is 1,1 GB.
I've restored it from NAS on the same PC.
I've done online updates and I've created an image file with Acronis again.
Now is the *tib image file larger than 3GB.

alright, now I understand what you mean.
And maybe that's perfectly normal, but your information isn't enough to be sure.

Look at the used capacity on that partition before making the image. I guess it's somewhere along 1.5 .. 2GB.
Look at the used capacity after you ran the updates: Is it considerably more?

The key to the explanation is probably data reduction and compression. By default, Acronis uses two methods to reduce the size of the image file:

It only backs up the blocks that are actually used, and ignores unused space. That's why the image isn't as large as the partition being imaged.
It creates a compressed image. Typically, you save about 30..50% space that way. However, the actual compression ratio varies very much depending of the data itself.

With that knowledge, it looks as though after the update there's a lot more space used on your partition than before. It's still an awful lot - considering a typical compression ratio, that would be a net growth of 3..4GB. Impressing, but not impossible. Maybe lots of temporary files left over?

[X] Doc CPU

cccc · 01-29-2012, 08:37 PM

Here is the disk capacity before any changes, recovered from a 1,19 GB tib image file:

Code:

$ df -mT
Dateisystem   Typ    1M‐Blöcke   Benutzt Verfügbar Ben% Eingehängt auf
/dev/sda1     ext4       11250      2408      8270  23% /
tmpfs        tmpfs        1009         0      1009   0% /lib/init/rw
udev         tmpfs        1004         1      1004   1% /dev
tmpfs        tmpfs        1009         1      1009   1% /dev/shm
/dev/sda7     ext4        1876        80      1701   5% /home
/dev/sda6     ext4         942        17       878   2% /tmp
/dev/sda5     ext4        2811       368      2300  14% /var

and here after updates:

Code:

$ df -mT
Dateisystem   Typ    1M‐Blöcke   Benutzt Verfügbar Ben% Eingehängt auf
/dev/sda1     ext4       11250      2430      8247  23% /
tmpfs        tmpfs        1009         0      1009   0% /lib/init/rw
udev         tmpfs        1004         1      1004   1% /dev
tmpfs        tmpfs        1009         1      1009   1% /dev/shm
/dev/sda7     ext4        1876        80      1701   5% /home
/dev/sda6     ext4         942        17       878   2% /tmp
/dev/sda5     ext4        2811       379      2290  15% /var

Now, if I do an Acronis image, then increases to 3GB!

Doc CPU · 01-30-2012, 04:21 AM

Hi there,

Quote:

Originally Posted by cccc

Here is the disk capacity before any changes, recovered from a 1,19 GB tib image file:

I guess we're talking about the root file system on /dev/sda1.

Code:

Dateisystem   Typ    1M‐Blöcke   Benutzt Verfügbar Ben% Eingehängt auf
/dev/sda1     ext4       11250      2408      8270  23% /

So that's 2408 blocks of 1MB size, about 2.4GB. If you get a 1.2GB image file, you have a pretty good compression ratio, but that's plausible.

Code:

Dateisystem   Typ    1M‐Blöcke   Benutzt Verfügbar Ben% Eingehängt auf
/dev/sda1     ext4       11250      2430      8247  23% /

Now there's 22 blocks more, which is negligible.

Quote:

Originally Posted by cccc

Now, if I do an Acronis image, then increases to 3GB!

That's weird - it would mean the compressed image file is 50% larger than the uncompressed data. Now I don't have a clue any more. :-(

[X] Doc CPU

cccc · 01-30-2012, 07:10 PM

Yep, that's really weird and still cannot find any solution.

cccc · 03-04-2012, 12:08 PM

Perhaps, this problem occurs after converting Ext3 to Ext4.
I've done a fresh Squeeze installation with Ext4 and it works well now.