DeviceImage Tools

[guest99]

From reading some of the articles here it sounds like zsplit backs up all sectors on a partition whether used or not.

Is there a companion tool that can be used to zero all unused sectors on a HD ? It would seem to me doing this this would increase the image compression tremendiously if the drive has been used alot.

Also it would seem like a good idea to zero a swap partition if there is one on the drive for the same reasons above.

If I have a blank unpartitioned HD will unzslip recreate everything except the MBR ?

thx

[jurij]

Hi,

Yes, the main idea of DeviceImage project is the file-system independent imaging tool.
Therefore the imaging procedure backs up all sectors (used+not used). There is only one exception, if your HDD has bad (or not readable) sectors all this sectors will be safely skipped (strictly speaking replaced with NULL sectors).

You are absolutely right saying that zeroing of unused sectors will be a good HDD preparation procedure which would increase the whole compression density. I have found in the Internet something which would be useful on that matter:
Please see here:
http://www.virweb.com/linux.htm#TOP
in the section "Preparing the Windows Partition".
But please keep in mind, I have not tested this tool so far. Therefore I would recommend you to do some extensive testing before you use it.

If you restore /dev/hda to /dev/hda the MBR will be also restored;
If you restore /dev/hda1 to /dev/hda or to /dev/hda1 - only partition hda1 will be restored and not MBR.

Regards,
Jurij

[Guest99]

I ended up doing the following while booted under sysrecue :


dd /dev/zero /dev/myswap_partition

then in my main partition I did :

cat /dev/zero >/temp.fill
rm -f /temp.fill

This created a file of 0's using all remaining space on the partition.

then I ran zslip on drive

This cut the image size in half on my system because of the
dirty sectors I had.


thx

[jurij]

Hi,

it is a really good idea !

Jurij

[NigoX2]

if you have a NTFS partition you can do something as well in Windows

first get cipher from Microsoft http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=89E5A2F2-E2A6-418F-90BB-345E95C89806

then type "cipher /W:C:", if C: is your partition
it writes 0x00 blocks
when it begins to overwrite them by 0xFF blocks, stop it by typing Ctrl-C (because the third round is to write random blocks, which we don't want)
go into your partition and delete the directory which was just created
that's it, your unsused blocks are blanked ;)