When taking an image of a drive, I am usually in a hurry since it is usually a preliminary precaution for a larger process. Gzip compression provides the best speed-size tradeoff when doing this since all but the slowest machines are primarily limited by disk speeds.
However, once I have the image, it would be nice to be able to crunch it down into one of the higher compression formats. Sure, I can expand it out in virtualbox and retake the image, but that's messy and uses a large amount of disk space. I could also crank the gzip compression up to maximum using advancecomp, but that uses a lot of memory, and doesn't like the image being cut into multiple pieces.
Is there a tool to recompress the images in place with a different algorithm? If not I will cheerfully undertake to write one, but I need to know if it would need to change anything other than the "gz" portion of the file name.
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No, Clonezilla does not provide such a tool for you. However, it's not difficult to make that by yourself.
Just remember to keep the naming style of the image file, i.e., for example:
if the image name of partition is save as "sda1.ext4-ptcl-img.gz.aa" in the image dir, you can gunzip this, and compress it with bzip2 or xz, but the name should be changed to "sda1.ext4-ptcl-img.xz.aa".
So, for example, if you want to convert it as xz format, with this command, you can make it:
zcat sda1.ext4-ptcl-img.gz.aa | xz -c > sda1.ext4-ptcl-img.xz.aa
Steven.
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I have made such a recompressor. It takes any image compression as input, and converts to zstd --long -19
Run this script inside a folder of images, and it'll recursively recompress all the images it can find. I've added safeguards for everything I could think of;
ensure that each image was made by a known-supported clonezilla ver
original image is verified against its included checksums (if any)
the recompressed image is compared against the original one
image is checked with partclone.chkimg after recompression
checksum files are updated to include the new files
original image is not damaged if this process crashes; work happens inside the subfolder repk of each image
skips images which have already been recompressed with the same compression settings
...so it should be absolutely safe to use -- and I've had zero issues personally -- but no guarantees of course :-)
When taking an image of a drive, I am usually in a hurry since it is usually a preliminary precaution for a larger process. Gzip compression provides the best speed-size tradeoff when doing this since all but the slowest machines are primarily limited by disk speeds.
However, once I have the image, it would be nice to be able to crunch it down into one of the higher compression formats. Sure, I can expand it out in virtualbox and retake the image, but that's messy and uses a large amount of disk space. I could also crank the gzip compression up to maximum using advancecomp, but that uses a lot of memory, and doesn't like the image being cut into multiple pieces.
Is there a tool to recompress the images in place with a different algorithm? If not I will cheerfully undertake to write one, but I need to know if it would need to change anything other than the "gz" portion of the file name.
No, Clonezilla does not provide such a tool for you. However, it's not difficult to make that by yourself.
Just remember to keep the naming style of the image file, i.e., for example:
if the image name of partition is save as "sda1.ext4-ptcl-img.gz.aa" in the image dir, you can gunzip this, and compress it with bzip2 or xz, but the name should be changed to "sda1.ext4-ptcl-img.xz.aa".
So, for example, if you want to convert it as xz format, with this command, you can make it:
zcat sda1.ext4-ptcl-img.gz.aa | xz -c > sda1.ext4-ptcl-img.xz.aa
Steven.
I have made such a recompressor. It takes any image compression as input, and converts to
zstd --long -19Run this script inside a folder of images, and it'll recursively recompress all the images it can find. I've added safeguards for everything I could think of;
partclone.chkimgafter recompressionrepkof each image...so it should be absolutely safe to use -- and I've had zero issues personally -- but no guarantees of course :-)
Download: https://ocv.me/dev/clonezilla-repk.sh
Last edit: trfl 2024-08-21
OK, great. Thanks for sharing that.
Steven