Compression decreases the size of data.

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Is it possible to perform Deduplication recursively?

If anybody is familiar with the concept of Deduplication (If not,read link on wikipedia) http://en.wikipedia.org/wiki/Data_deduplication Is it possible to perform Deduplication recursively i.e. ...
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221 views

How do I access gzip-compressed data from a PowerShell Invoke-WebRequest command, when the “Accept-Encoding: gzip” header is set?

I'm learning about response compression in IIS and I'm testing my configuration with various tools. It appears that several of these tools either auto-decompress the response, or always send the ...
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50 views

Linux equivalent settings for 7zip

I'd like to use the same settings as below (Win7) on Linux to compress files, but I fail to get equal compression results, for which I blame myself not correctly using 7za. So far, I have 7za a ...
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4answers
563 views

Is it faster to compress files before copying? [duplicate]

I have around 80 GB of data I need copy to an external hard drive. Would it be faster to compress all the files first and then copy over? Or would the time it takes to compress and decompress take ...
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1answer
57 views

How is this RAR archive able to achieve such a good compression ratio?

The RAR archive found here (direct download) contains a single AVI video file which is 42MB in size. The RAR archive is only 500KB. How can the archive achieve such a high compression ratio?
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37 views

Changes in level of compression between different versions?

I used the save function with xz compression as in save(a, b, file = "c.RData", compress="xz") This produced a file of different size on my disk (11589212 vs. 1162284 bytes) switching from R.3.1.1 ...
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1answer
155 views

tar reverse of '--to-command', or: compressing tar entries individually, or: tar with plenty of large files

I would like to create tar gzip archive, but do it the reverse manner of what is most commonly done -- have the files in the archive be compressed individually rather than compress the entire archive: ...
2
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0answers
242 views

Why do IPSec VPN Compression and Windows Remote Desktop not work together?

I just discovered a strange problem. I connect to a remote network via VPN. Within this VPN is a separate Microsoft Small Business Server (which does not provide the VPN, another device does this). So ...
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1answer
54 views

Deleting unpacked tar.gz files after unpacking incorrectly

I recently unpacked a set of backup files in RHEL3 - 2.4kernel with tar via: tar -xvf backupfile It started to error out a bunch and I aborted thinking that maybe it was a gzip instead. Unpacking ...
2
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1answer
113 views

How to open multiple TGA files then save them compressed as 24 bits in Photoshop?

I have a huge amount of TGA files from the game Counter-Strike (environment files such as sky, grass, water etc) and they are pretty big. There were some other TGA files that I manually opened and ...
3
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1answer
215 views

Not sure gzip has decompressed the whole file

I am decompressing a list of files using gzip: At any time it skips from one file to the next, I read (I am using the verbose option): star_60out.txt.gz: 91.0% -- replaced with star_60out.txt or ...
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0answers
109 views

Is there an alternative to httpfs2 to mount web urls in Linux?

Currently I use httpfs2 to mount direct web urls in the filesystem. For example a rar archive which has to be decompressed, but I don't have enough space on my VPS to download AND then decompress the ...
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1answer
29 views

Can i save modification in compressed file folder? [duplicate]

When modifying documents that are directly opened from compressed file folders like RAR or Zip, I normally close them without dragging the files out of the rar or zip file. I used to do this in the ...
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2answers
79 views

Determine type of archive file in Linux

I have an archive file with .tar.gz as extension grabbed from http://www.oracle.com (it is the Java Runtime Environment). I tried to decompress it using tar -xvf and tar -zxvf and it says gzip: stdin: ...
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3answers
74 views

decompressing a 50 GB archive to a 100 GB drive

So I moved hosts today and I put all content from the old host into a single archive. The archive took 20 minutes to compress and one hour to transfer the tar file to the new host (Linux CentOS ...
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0answers
26 views

How to make to identical sized archive parts with rar archiver?

I am trying to compress a file with option -v but I am unable to figure out the byte count to set, yielding two identical sized archive parts (part1,part2). My original file size is: 1068303782 bytes. ...
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68 views

True crypt container issue

I had created a true crypt container in my external HDD but stupidly ticked the "compress contents to save disk space" option from file properties. Now when I attempt to mount my container with true ...
0
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1answer
187 views

Create Compressed Back Up Image Mac Mavericks

I have a 3TB external drive, that for some reason is partitioned as a single Master Boot Record partition. Seagate, go figure. I'm running a 1TB Mac with 10.9.4 and about 380GB used space. My ...
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1answer
301 views

zip file (with spaces in the files name) to unzip and rename files and zip back

I'm trying to rename the contents of a zip file to match the name of the zip file with a batch file. This is exactly what I'm trying to do : ...
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3answers
92 views

Reduce bandwidth usage when web browsing? [closed]

If I have a 1GB tethering allowance per month. Is it possible to somehow compress the websites I visit so they use less bandwidth to reach my screen?
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1answer
67 views

Creating a shell script to compress files using Cygwin [closed]

I've got a minor project wherein I'm to create a few shell scripts in Windows and run them through Cygwin for Linux files. At least that's how it was described to me. Any suggestions would be great.
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0answers
27 views

Is there any way to have the `split` utility gzip its output by default?

I'd like to be able to do something like, my_long_running_process_producing_lots_of_output | split --gzip --lines 1000000 - part_ and have this produce things like part_aa.gz part_ab.gz instead ...
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2answers
3k views

Cannot decompress .tar.xz file, getting “xz: Cannot exec: No such file or directory” from tar

Per How do I uncompress a tarball that uses .xz?, I tried tar xf php-5.6.0RC4.tar.xz and tar -xJf php-5.6.0RC4.tar.xz and in both cases I get the following: tar (child): xz: Cannot exec: No such file ...
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19 views

Compressing an OS after some slight changes has yielded massively different results - why?

I am using SUSE Linux on a Virtual Machine through VMWare Workstation. This morning, I zipped up a copy of the folder containing my VM (.vmx, .vmdk, .vmem, single snapshot and all) and sent it to my ...
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22 views

Copy image/disk/partition, not necessarily entirely and with compression for image

As my last question was considerated "off-topic", here it is reformulated : I have a 16GB SDCard but I put 4GB image on it and I want to be able to extract&store compressed only the 4GB image ...
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1answer
106 views

Bulk resize / compress TIFF files [closed]

We support and host an EMR for several medical practices; these practices scan images into this software stored as flat files (TIFF mostly). Due to poor user training (people scanning text pages as ...
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1answer
1k views

Adobe photoshop “not enough ram” message opening a 60 MB TIFF file

I am working with Windows 7 x64 on a full HD monitor, Intel i5-2500K and 8 GB RAM, currently available 5,5GB. I tried to extend photoshop's memory usage and scratch disk settings as following: But ...
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41 views

Zpaq does not accept option “method”

I am trying to run the command: box:~/experiment# zpaq a out out.m4v -method 5 This should compress out.m4v to the file out using the method 5 but instead I get the error. -method: No such file ...
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1answer
4k views

7-Zip: Unsupported Compression Method while trying to extract a zipx file that consists of JPEGs

A zipx file I received consists of .csv files and .jpeg files. I used 7-zip to extract them. While the .csv files were sucessfully extracted, the JPEG files didn't. The error was something like this ...
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2answers
670 views

What does combining compression methods in 7z actually do?

The 7z command-line tool lets you specify multiple compression methods, e.g.: # 7-zip archive type, strongest (9) compression, methods PPMd, BCJ2, LZMA2 $ 7z a -t7z -mx=9 -m0=PPMd -m1=BCJ2 -m2=LZMA2 ...
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4answers
708 views

How to batch compress images with Imagemagick or similar command or program in Linux

I recently learned about the convert command from imagemagick which I have used to compress many pictures that I have for personal use, and for a blog that I have. In my experience, Imagemagick is the ...
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259 views

How to NTFS compress the system drive?

As you know, some files cannot be compressed when your system is running. How do I enable compression system-wide then? For every single file? Can I enable it in the recovery console? Ps.: For ...
0
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1answer
242 views

Should I compress the harddisk file in a virtual machine?

I have a virtual machine with Windows 7 32-bit installed, and the host is Windows 7 64-bit. I have chosen dynamically resizeable VDI disk image. After installing Windows on the disk image, it is about ...
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1answer
180 views

What 7zip settings to compress very large partition image?

I have 77 GB big partition backup image in single file and I'd like to compress it quickly. It should compress very well even on worst settings, but choosing GZIP with "Fastest" setting takes about ~1 ...
0
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1answer
236 views

Merging many .rar files in one .rar file

I have about 200GB of rar part files (all .rar) that I would like to merge into 1 single .rar file. I'm trying to perform this in Windows. How would one go about merging many a rar file without ...
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1answer
101 views

Compress / Zip a folder periodically but use minimal CPU?

Similar to this question except, I need it to run with minimal CPU on the background? Also, if there's a 7zip solution that will be nice.
3
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0answers
46 views

Compressed file with a header containing all files within it, at the beginning of the file

I have noticed that most files resulting from a compression / archive process do not have a list of the files contained at the beginning of the resulting file, but rather at the end of it. For ...
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0answers
33 views

Store disc images on a hard drive

I'm cleaning up around my computer (A Win7 ultimate machine), and part of my plan is to rip all my program CDs and store them on a dedicated 1TB hard drive. My initial plan was to simply dump the ...
3
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1answer
77 views

Is there any solution/utilities to compress and upload a large file simultenously?

Upload a large file via broadband connection takes time. Compress the file using max. compression ratio before upload also consume time. Is there any solution that may compress and upload file to ...
0
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1answer
22 views

Compressing with BarCat?

I'm having an issue using Barcat to show a dialog while compressing? Wondering what the exact syntax is? here's a link to Barcat things I've tried are bar -n apache24.tar.xz |tar -Jcf - bar -n ...
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179 views

Improve slow NAS Ethernet transfer speeds: On-The-Fly Ethernet Compression with SAMBA?

Hardware: Pogoplug E02 (ARMv5te, Marvell Kirkwood 1.2GHz, 256m RAM) Software: ArchLinux, MDADM RAID 5 array, Ext4, SAMBA server This setup delivers file transfers to my Windows clients at ~21MB/s ...
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2answers
532 views

How can I achieve the maximum zip compression? [closed]

I would like to make a "standard" zip file which contain .jpg images. Which software and switches / options should I use to achieve the maximum compression ratio? I mean maybe I can make a solid ...
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0answers
166 views

Compress 1 TB file collection into standalone archives each size no more than 2GB

I have about 1TB data stored in two drives and I need to compress and encrypt them into independent archives each size must be smaller than 2GB. Exception may be files that are larger than 2GB. Is ...
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2answers
651 views

NTFS compressed folders: is it possible to tweak compression ratio?

As it seems, Windows compresses the NTFS compressed folders with the lowest compression ratio possible. While this maybe good for increasing speed and decreasing CPU load, for the files that are ...
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0answers
60 views

Tape backup with compression

I would like to backup a NAS to a series of LT02 tapes, (200 gigs uncompressed, 400gigs compressed.) There are about 700 gigs of data to back up. I initially tried cpio, first trying to set hardware ...
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2answers
12k views

What is the difference between rar and RAR5 compression?

What is the difference between rar and RAR5 compression ? Which is better for which purpose vs the compression time.
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1answer
976 views

Recursively process zip archives to extract files while discarding specific format of files

On my Windows 7 machine, I have a directory full of downloaded dumps in ZIP archives. Each archive contains few text files, PDFs and rarely XML files. I want to extract all the contents of each ZIP ...
0
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1answer
121 views

How to have zpaq extract files to stdout

I have some log files compressed with ZPAQ that I do not want to extract to disk every time I need to go grep-ing for events. Would like to extact to stdout so I can handle the output the same way as ...
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2answers
95 views

I cannot open folders in .tar file

I've downloaded factory image for my Nexus4 mobile, the Image folder is compressed in .tar file but it tells me that its unknown file Type: File ,, how can i open it? here take some photo of my ...
6
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3answers
272 views

When putting two identical files in a .zip, they take 2x space, can this be avoided

Say that you have a file you want to put in a .zip archive: zip a1.zip foo.dll My test .dll file is ~10MB, and the archive turns out to be 3.5MB Then you create a file with the exact same ...