GZip + IMG compression problems
Posted 11 December 2011 - 04:50 PM
i created 3.8GB image (x.img) then downloaded gzip.exe and ran the command
gzip -1 d:x.img
the compressed image size is 514MB
Next i ran this command while x.img was mounted on xp
and updated x.img with img_xp_update.exe
now when i compress, the size is 3GB+ O_O
I defragmented still size not going down!! what went wrong? i also tried with 7zip, still 3GB! why free space not getting compressed?
Posted 11 December 2011 - 05:41 PM
maybe such tool can again help gzip.exe compress only data and not the empty space.
Edited by ignored, 11 December 2011 - 05:43 PM.
Posted 12 December 2011 - 12:26 AM
to compress extra by gzip
you can do that by this command
gzip -[color=#ff0000]9[/color] file.img
9 is the maximum compress and you can use some other parameters
by change the number from 9 to 1 it is less compression
and normal compression use 6
Posted 17 December 2011 - 02:44 AM
at first i got this result when i didn't touch the empty space but when i ran "sdelete.exe -c" to clean empty space inside image, everything became slow.
compression with -1 which is 8MiB/s became slow because freespace was getting compressed badly. So .gz is high in size, resulting in slowest boot.
I am going to create brand new empty image, copy files from previous image to new and try gzip -1 again. i think this will mostly work
if i go for your option "-9" compression time of 3.8GiB image will irritate me.
Edited by ignored, 17 December 2011 - 02:46 AM.
Posted 17 December 2011 - 04:13 AM
inside 3.9GiB image, only 1.09GiB is used.
x.img.gz map memory speed is very slow on my ssd, 30MiB/s approx but when data part is mapped, empty space goes like 300 or 400MiB/s which is very good.
In the middle however, it becomes slow for 6 to 7 seconds. To verify, i mounted x.img and analyzed with UltraDefrag. There is free space in the middle, when i defragmented, gzipped image went above 850MiB!!
UltraDefrag's strategy of moving files at the end of disk and then moving back optimized files to beginning used free space! Once the free space is used up, gzip algorithm gets hard time!
Edited by ignored, 17 December 2011 - 04:26 AM.
Posted 17 December 2011 - 06:47 AM
Furthermore, the reason why CCleaner had solved this is because it has options and functionality to clear out that temp data, (not all of it though). So you will never have 100% of that free space logically for that reason, from system properties. It tells you because your system knows that at any given time you could never fill the partition with that free data space immediately.
Posted 17 December 2011 - 02:20 PM
does any of you know of smallest tool:
- to clear free space
- to save partition or disk to .img from dos
- to resize partition with different formats, linux, windows,
- to defragment