Compression decreases the size of data.

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0answers
17 views

Does hard drive compression give a performance boost? [duplicate]

I recently formatted a hard drive and was asked if I wanted to enable file compression. I remember hearing a long time ago that as computer processing power improves, it would make sense to have all ...
15
votes
6answers
13k views

.tar files without directory structure

I'm .taring some files with the path example/super_user/Output.*. The resulting .tar looks like this: + example + super_user - Output.zip - Output.xml - Output.txt ...
0
votes
1answer
29 views

Which level of compression should I use a .iso file [duplicate]

I have a .iso file on my hard drive (on a windows 8 pc) and it is really big (something like 16 GB). I was trying to compress it (using 7-zip) so it could fit on a DVD-R. But when it finished ...
2
votes
2answers
59 views

How to compress extremely large file in place

I need to compress a 646.4GB file on a 1TB external HDD. This HDD currently has about 238.6GB free. However, since the straightforward compression methods create a new file, I'll not be able to ...
106
votes
6answers
216k views

How to decompress a .bz2 file

I have a file as: filename.bz2, but I can't figure out how to decompress it. I tried several methods, none of them seems work. I have tried the command: tar xvjf filename.tar.bz2, but it didn't work ...
1
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1answer
3k 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 ...
0
votes
4answers
82 views

How to open tar gz file created using tar piped to gzip

I wanted to generate a tar gz file with the highest compression level, and I followed the solution from http://superuser.com/a/546509/461740: tar cv /path/to/directory | gzip -9 > file.tar.gz ...
1
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2answers
3k views

7-zip command line -p switch not working according to help page

I want to be able to automate the encryption of the file type .pcapng in a windows batch script. My current problem is that I get an error when extracting the encrypted file saying something along the ...
10
votes
5answers
8k views

Mac OS X not reporting directory sizes correctly?

In Finder, I've noticed that if I duplicate some .app files (in the Applications folder), Finder will show that the duplicate .app file is not the same size as the original. This file size ...
0
votes
1answer
31 views

.zip corrupted on Mac

I've got a .zip file of approx. 20GB. (20,497,570,063 bytes) I am trying to uncompress it but both Archive Utility and Terminal are failing to do so. Archive Utility is giving error 2 (no such file ...
66
votes
7answers
20k views

Compress and then encrypt, or vice-versa?

I am writing a VPN system which encrypts (AES256) its traffic across the net (Why write my own when there are 1,000,001 others already out there? Well, mine is a special one for a specific task that ...
0
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0answers
19 views

regex search compressed password protected files

I have a repository of a few million large text files. I need to regex search them on a regular basis. Because they are large, I use gzip to compress them and zgrep to search them. I have been asked ...
0
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0answers
56 views

How to recursively extract a zip bomb?

I downloaded the famous 42.zip zip bomb and was able to extract it in my computer without my system crashing. Then I realized that in order to see the effects of the bomb, I will need to recursively ...
21
votes
3answers
36k views

Is it possible to execute a file after extraction from a 7-Zip self-extracting archive (SFX) archive?

I'm try to make a compressed deploy-able application. Currently I'm taking a set of files that I've published from my IDE (Visual Studio 2008 - WPF published application) and compressing ...
1
vote
1answer
485 views

Need to read a Windows 98 DRVSPACE.000 file in Windows 7

Today I came across a DRVSPACE.000 file in my archives and I want to recovers its contents. Beside the file is a READTHIS.TXT which reads: This disk was compressed using DriveSpace 3, which ...
2
votes
0answers
31 views

Unzip .gz file when line order is important

I am trying to unzip fastq.gz files and then analyze the sequencing data within them. However, later analysis is dependent on preservation of line (line 1 from zipped file must be line 1 in unzipped ...
2
votes
1answer
42 views

PNG or JPEG for an X-Ray without visible artifacts

A past paper question from a Multimedia Systems exam: If you had an X-Ray photograph of a leg which might be broken, which would give better compression before artifacts were visible, and which ...
0
votes
1answer
21 views

Unix gzip more than one file at once

I have come to the end of my research with unix:> I'm new with unix and its enviroment, so i need your help guys. Long story short, i have a housekeeping script, which runs daily/weekly (it doesnt ...
1
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1answer
36 views

“Compress contents to save disk space” option not available for one partition

One of the partitions on our Server 2003 R2 server recently ran out of free disk space. After freeing up a significant amount of free space (20 GB, which only corresponds to 1.37% of the partition - ...
0
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1answer
20 views

NTFS Compression on multiple folders

I have been tasked with compressing certain folders on a network drive. The drive is formatted NTFS on a Windows Server 2008 R2 machine. The folders to be backed up are all called "Backup", and are ...
0
votes
0answers
11 views

Will archiving little-used directories in my Dropbox folder increase the indexing speed?

I have 14336 files in my Dropbox directory. Many of these are in old projects that I don't touch any more, but that I like to keep around in case I need them. I know that Dropbox holds an index on ...
0
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1answer
26 views

Jpegtran made images bigger

I ran jpegtran on a bunch of images as such: $ jpegtran -copy none -optimize Most of them were reduced in size by a lot. But some of them actually increased in size. How can that be?
-1
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2answers
56 views

What kind of image compression causes this color banding? [closed]

I have two images. The first is before undergoing lossy compression: Picture #1: The second is after undergoing lossy compression: Can anyone explain to me what is going on here? How does this ...
1
vote
1answer
45 views

7zip Batch Compression for a specific file extension in different folders

I've already learn how to batch compress my files as-is with 7zip but I have something more complex need on this issue. Maybe I can explain my needs with this scenario; I have a backup folder of my ...
0
votes
1answer
12 views

No 'Compress this drive to save disk space box"

I have two external hard drives, both with NTFS, one of them allows me to compress it, the other doesn't, why? https://goo.gl/photos/AqV5V42dEY5N2o569 I deleted titanfall and bf4, freed up some ...
0
votes
1answer
37 views

Gzip compression on Apache using .htaccess

As per http://gtmetrix.com/enable-gzip-compression.html i'm trying to enable gzip compression on apache webserver adding code mentioned below in .htaccess, but it's not working ; can you please ...
0
votes
1answer
41 views

Determining Cause of Unexpected Shutdown on Windows 8.1

I left my computer unattended a little over half an hour while it was compressing some files. I came back, and my computer had apparently shut off. I looked at the Event Logs, and it told me that The ...
2
votes
2answers
65 views

How to compress serveral, large, high entropy, but very similar files?

I have several big (as in: bigger than any dictionary, 100s of GBs) files. These files are very high entropy and compress very poorly. However these files are (as far as i can tell) almost completely ...
0
votes
1answer
40 views

Windows 7 compressing doesn't reduce space [duplicate]

I used the compression method by windows 7 from the properties of a file but it doesn't seem to work. The folder that was around 42,6 Gb is now 42,5 Gb which means it only saved me 100 MB? Is there ...
0
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0answers
16 views

“recompress” a 7z archive inline

I have a rather large (~500GB) 7-zip archive. I originally made it when I had more space available, and did so at rather fast, low-compression settings. Now things are tight, and I'd like to try and ...
0
votes
1answer
36 views

Incorrect size of image file made with dd and gzip?

In the past I made a backup of a partially full partition with dd if=/dev/sda1 | gzip -5 > file.gz. Some time later, when a free space on partition was smaller I made an image file again with the ...
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votes
4answers
39 views

Why isn't it possible to Encrypt and Compress a Folder on Windows?

I read this blog which explains why this isn't possible but I can't seem to figure out the reason. I find the blog a little difficult to understand. Can someone please explain why it's not possible ...
0
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2answers
46 views

How to know the compression level of a PNG file and whether it is lossy?

Can I know whether a PNG file was compressed and how (at least, whether it was a lossless compression) in Windows? When I open the standard file properties dialog from the Windows Explorer, I see no ...
1
vote
2answers
60 views

What was the SquashFS compression method?

I've got some SquashFS files, and I'd like to know how they were compressed so that I can have a rough idea of how they would perform when mounted. The only binaries provided by the squashfs-tools ...
7
votes
5answers
5k views

How to open corrupted ZIP files?

How can I open (or repair) corrupted ZIP files on Windows? Is there a way to force 7-Zip to open them?
1
vote
1answer
53 views

lighttpd complains about ssl.use-compression

I am trying to apply some of the tricks described here, and the problem is having ssl.use-compression = "disable" in lighttpd.conf, because server reports WARNING: unknown config-key: ...
0
votes
1answer
25 views

Decompress files in subfolders to the same subfolder using 7-Zip

I have a set of subfolders with .gz files buried in them. I need to decompress the files and keep the directory structure the same. I have used for /f "usebackq" %i in (`dir *.gz /s/b`) do 7za x %i ...
2
votes
2answers
60 views

Which lossless image codec can achieve the highest compression ratio on photographs of buildings? [closed]

I was wondering which lossless image codec is best for compressing photographs* if we only care about final file size? * scanned negativs specifically Additionally does it make a difference if the ...
1
vote
3answers
4k views

How to extract multipart rar with missing parts?

I have a multipart .rar archive containing a single .tar.gz file inside it (don't ask why, that is just how it was made). I am missing a few of the parts, but do have the first part. I would like to ...
0
votes
2answers
52 views
10
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4answers
5k views

How can I compress a file on Linux in-place, without using additional disk space?

I've got a 100GB drive that has a 95GB file. I need to free up some space on the drive (and right now transferring the file off the drive is not an option). The file would compress well with gzip or ...
1
vote
1answer
45 views

Excel conditional drop down lists causing massive file size

I have an excel file which relies heavily on data validation. There are about 20 drop down lists per row. One column has a 35 formatting conditions. One column is a conditional drop down list (using ...
0
votes
1answer
36 views

How to recursively compress subdirectory's files with password

I need to recursively compress subdirectory's files with password and then delete the uncompressed file in bash file. There are zip files and other files. I don't want to compress zip files again. I ...
0
votes
1answer
40 views

Does unzipping a file on a remote server download the files back to my local?

I need to copy a high number of files to a remote windows server. I am connecting to it via VPN and then browsing to the remote folder in Windows Explorer. Problem is uploading is really slow, ...
0
votes
0answers
33 views

How to create a highly compress self extracting archive with 7zip or winrar?

I have downloaded a highly compressed call of duty modern warfare highly compressed 99 mb self extracting 7 zip archive .after extraction it becomes 6.35 gb how they compressed these things .i know ...
1
vote
1answer
50 views

I can't get compress.exe to produce anything

I'm trying to emulate the Windows Send to/Compressed (zipped) folder function using the Microsoft tool compress.exe, included as part of the Windows Server 2003 Resource Kit. It might not be possible ...
0
votes
1answer
40 views

Losing storage space on Windows 8.1 by compressing and decompressing the disk [duplicate]

At first I thought if I compress the disk, then I would get extra space. However, after doing the compression I lost 2.5GB. Then, I decompress the whole disk to regain the lost 2.5GB but I lost 1GB ...
1
vote
4answers
479 views

Does 7zip compression level affect decompression speed?

I have a directory that I would like to password protect and encrypt. I am using PeaZip to do this using 7zip compression. I'd like to use the 7z like a directory and hard drive space is not a ...
0
votes
0answers
67 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 ...
2
votes
2answers
66 views

Container with in-built compression, which automatically adjust its size

I try to find an efficient way of rsyncing contents of an ext4 file system as a part of a regular backup, yet I consider a decent compression and a minimal required space. I can just use plain rsync ...