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View Full Version : Compression with drive image backup



firebyrd10
07-28-2004, 11:37 PM
Everytime I've backed up a 8 gig hardrive, I've had to manually make a zip file of the resulting image, the drive it self is composed of highly compressable data, (free space, tiff images, RTF documents) which bring the size down to about 4 gigs, What I want to know is, is there a way to atomaticly gzip(or what ever is the best) the data as its being backed up (I'm useing dd, to a samba server). I understand it would take significanlty longer.

Also I'm currently useing this

dd if=/dev/hda | split -b 100000000 - ~/backup/drivebu.img. to send the data to a remote samba server. Though I want just one big file, so would this work?


dd if=/dev/hda of=~/backup/drivebuimage.img

Thank you.

firebyrd10
07-29-2004, 06:51 AM
If its any help here is how to do it with SSH


If you want to compress the image, use gzip, making necessary changes for your system
dd if=/dev/hda | gzip --fast -c | ssh user@remotehost /bin/dd of=/tmp/mypc_hda.img.gz

firebyrd10
07-31-2004, 05:06 PM
alright I got it.
To make one,


dd if=/dev/hda(or other drive) | gzip -(1 through 8 with 1 being fastest and 8 having best compresion, --fast =1 --best =8) -c | dd of=~/sambabu/hda.img.gz
and to restore


xcat ~/sambabu/hda.img.gz | dd of=/dev/hda

sakiZ
01-24-2005, 09:30 PM
Pardon the newbie question.

Having recently backedup to an UNCOMPRESSED image file recently, I was wondering if you can use Xcat to restore the partition.

sakiZ

firebyrd10
01-25-2005, 12:38 AM
just cat instead of xcat

sakiZ
01-25-2005, 05:49 AM
Ok I restored my Knoppix partition from an image file.

But now after booting for a few seconds, it suddenly stops with a "kernel panic" message. wiith messages saying "file type not supported.

Yet, I boot with the CD and I can see the whole partition restored. I just can't boot from it.

What is going on?

sakiZ

sakiZ
01-25-2005, 06:14 AM
Ok. Knoppix likes files system ext2

But in the process of "dd" ing from the hdb2.img file to the /dev/hdb2 partition, the partition becomes changed to ext3.

But how do I stop the "dd" process from converting the partition to ext3?

sakiZ

firebyrd10
01-26-2005, 12:40 AM
Ok. Knoppix likes files system ext2

But in the process of "dd" ing from the hdb2.img file to the /dev/hdb2 partition, the partition becomes changed to ext3.

But how do I stop the "dd" process from converting the partition to ext3?

sakiZ

Never heard of that problem,

dd is suppose to make a bit-for-bit copy.

Something might has gotten corrupted.

Next time I would md5sum the files first. (acually I would reccomend you use partimage)

just tack this on the end of the command.

&& cat /dev/hdb2 | md5sum && cat ~/image.img | md5sum

Then compare the resulting string of numbers and letters, if they aren't the same, something went wrong.

Like I said before though, use partimage I learned alittle latter that its better.

sakiZ
01-27-2005, 04:47 PM
Yes, Something got corrupted during the dd process. I don't think I'll use the dd to an image again.

It screwed up my ability to boot, but after a reinstall I was able to loop mount the hdb2.img file and copy all data, personal files and such into the new install.

Knoppix is running fine now.

Oh Well.

SakiZ