Compression decreases the size of data.

learn more… | top users | synonyms (1)

2
votes
2answers
221 views

Modern command line file compression utilities

I am frequently moving large files around from server to server. UNIXes comes with standard gzip and bzip2 compressors. However, what open options there exist beyond these, especially ones utilizing ...
1
vote
3answers
2k views

Is there better compression than RAR? [duplicate]

Possible Duplicate: Compressing with RAR vs ZIP As many will know, the RAR format produces consistently better results than ZIP. I've used RAR happily for many years and it's really ...
1
vote
1answer
61 views

Extract files to a different folder

On a Windows XP machine, I have a zip file located on "c:\temp\mydata\okidata.zip". Using 7-Zip application, I would like to write a batch script and extract the file silently to the following ...
0
votes
1answer
317 views

How does the CentOS/Linux zip utility handle files that are changed during compression?

Question says it all: I have a directory that I want to 'zip -rv' up, but the files are changing all of the time (postgres database base backup). Will this break zip, or will it continue with a ...
11
votes
5answers
11k 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 ...
6
votes
1answer
2k views

Compressing a file in place - does “gzip -c file | dd of=file” really work?

In the question How can I compress a file on Linux in-place, without using additional disk space?, one answer proposes to simply use gzip -c file | dd of=file I tried it (on Debian Linux), and it ...
1
vote
1answer
2k views

How should I compress my network traffic? How to make my connection 'faster'?

I have a slow ADSL currently, which could really benefit from some compression. I've also got servers in the country, with a very low ping (0, 1ms to the my ISP). Which software, 'solution' should ...
13
votes
4answers
8k 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
3answers
1k views

A compression (online) service?

Mysteriously, our connection is now very slow (10 KiB/s), so it takes a very long time to download large files (>= 900 MB). I'm searching for an online service that will: Download the original file ...
0
votes
1answer
466 views

Weird GZip / Disk space issue

I'm working on a server which is using PCI Compliant partitioning rules, which means that each of the following directories has its own partition: /, /var, /boot, /usr, /tmp and /home. The server is ...
2
votes
0answers
414 views

Does a smaller cluster size increase the ratio of NTFS compression?

I read that NTFS compression needs a partition formatted with an allocation unit size <= 4KB. Could a smaller cluster size of a partition give more compression and lessen wasted space? For ...
2
votes
3answers
1k views

Create multiple zip files that are not dependent on each other?

I want to compress a folder into multiple zip files of 50MB each but don't want them to be dependent on each other. When I use Winzip and use the split feature it creates one zip file and the others ...
2
votes
1answer
2k views

Is it safe to compress my Windows 7 %USERPROFILE%\AppData folder?

Having just read Scott Hanselman's latest blog entry, Guide to Freeing up Disk Space under Windows 7, he suggests turning on NTFS compression which I already do for a number of less travelled folders ...
23
votes
2answers
42k views

What do the numbers 240 and 360 mean when downloading video? How can I tell which video is more compressed?

I have downloaded some computer science lectures from YouTube recently. There is usually more than one choice of file size and file format to download. I noticed that for the same video, the ...
8
votes
3answers
9k views

How do I convert tar.bz2 to tar.gz?

I'm new in Linux, is this conversion possible? Do I need to compress and decompress all content?
5
votes
3answers
3k views

Can compressing Program Files save space *and* give a significant boost to SSD performance?

Considering solid-state disk space is still an expensive resource, compressing large folders has appeal. Thanks to VirtualStore, could Program Files be a case where it might even improve performance? ...
2
votes
2answers
2k views

Why do bzip2 and gzip corrupt large heapdump files and can I work around it?

I'm trying to analyze heap dumps from a server which are fairly large files (10-15 GB). I create those files on the server and want to analyze them on my machine, so for downloading them, I tried ...
0
votes
1answer
137 views

Unzip delete and unzip

I am having an issue with commad line unzip and am not sure how to correct this. I am unzipping a compressed file and it processes it correctly. If the zip file should have some files removed and it ...
3
votes
3answers
1k views

If you switch NTFS compression on, why is the CPU load so low? Does it use SSE4.2 instructions behind the scenes?

I have a Hex-core Xeon X5650 running Windows 7 x64. I'm currently doing simultaneous compression of three NTFS hard drives, 2TB each, with the commands: compact e: /i /c /s compact f: /i /c /s ...
2
votes
3answers
558 views

How do I create a Windows XP compressed folder in Winzip?

When you create a compressed folder in Windows XP it appears to be a standard zip file but it's not. That said WinZip 9.0 (dated 2004) can read it. However the Windows XP compressed folder support ...
4
votes
2answers
13k views

Untar a given linux tarball on MAC OS X

I have a Linux tarball that can't be unpacked. It gives me an unexpected error. I am told this is due to case insensitive on MAC OS X. How can I untar this file? tar -zxvf file.tar.gz ... x ...
0
votes
1answer
433 views

compression for large Maildir structure

I run a Debian Linux mailserver for a few little companies that stores its emails in a Maildir structure and therefore each mail as a seperate plain text file. Altogether these files are as large as ...
1
vote
0answers
100 views

IIS vs httpZip (or other product) Compression

We're currently comparing httpZip compression software. Has anyone used this and can offer a comparison between that product and IIS? Is there a big savings for httpZip over IIS? If you aren't ...
9
votes
2answers
12k views

How do I use 7-Zip for Windows to create .tar.gz archives?

How can I use the 7-Zip CLI (7za.exe) on Windows to create .tgz archives, as I use tar zcvf archive.tgz source_files on Linux?
1
vote
1answer
29 views

copying a directory tree to another location, with optional compression

What I want to do is to copy a directory to anther position (on Linux), and compress some files (with a certain extension) with GZip on the destination, while other files are just copied. Could this ...
3
votes
2answers
10k views

Piping in and out of tar and gzip

I am trying to get a handle on how to pipe from a command into something like gzip, cpio or tar. The commands in question belong to the ZFS system. I am running ZFS on Ubuntu Linux 10.04.3. The ...
2
votes
1answer
423 views

How can I compress multiple files into three files per archive with 7-Zip?

I have 100 files that look like this: 001.txt 002.txt 003.txt 004.txt ..... 100.txt I want to compress them like this: 001.txt 002.txt ----> archive01.7z 003.txt --------- 004.txt 005.txt ...
1
vote
4answers
2k views

What are the most popular file extensions for COMPRESSed files? [closed]

I was just wondering, what's the difference between these file formats? Shouldn't there be just one or two that generally tend to perform superior to most others?
1
vote
3answers
730 views

Hash of a 7-Zip archive of a SVN export changes even when the files don't change. Is this by design?

I'm writing a PowerShell script that does the following. Does an SVN export of a Subversion repository to a temporary folder Zips the contents of the temp folder into a 7-Zip archive Compares the ...
16
votes
4answers
21k views

How to do “Files to store without compression” in 7-zip?

Is there any way to selectively prevent certain file types from compression in 7-zip, like in WinRAR? I'm trying to compress a huge folder (many gigabytes), and I don't want the already-compressed ...
4
votes
1answer
1k views

Auto self extract archive with password…Is it possible?

Is it possible to make an password protected SFX archive (non GUI) and extract it by giving a password via command line ? Do any of the archive formats support this ? I couldn't find any. ...
0
votes
2answers
54 views

Maintain bzip2ed directories on Windows

I have a folder that, besides other things, has folders named after dates, e.g. 20110908 20110909 and so forth. Every night, I would like to run a tool that checks for all folders matching that ...
4
votes
1answer
1k views

Why does compressing and decompressing my SSD hard drive free up space?

I bought an SSD (SandForce 2), created a tiny 25GB partition on it for Windows and installed Windows 7 64-bit. In order to free disk space, I enabled compression on the drive using the Properties ...
6
votes
2answers
1k views

Which compression program/algorithm produces the smallest archive file?

I have a directory full of *.avi files. I'd like to compress this directory into an archive of the smallest possible size. What compression software would produce the smallest archive file?
2
votes
1answer
352 views

How to safely zero fill a file in a compressed filesystem in Linux?

I had read that the shred doesn't safely work for compressed filesystems when shredding a file, how this can be accomplished in a compressed fs ?
5
votes
3answers
273 views

Arrange JPG images based on JPG compression/quality

I have been looking for a way to arrange JPG images based on the quality/compression level of the images. I want to do this so that I could select only those images which has less compression (let’s ...
3
votes
2answers
9k views

How can I compress a large file into smaller parts?

I'm looking for a way to compress a large file (~10GB) into several files that wont exceed 150MB each. Any thoughts?
2
votes
1answer
448 views

How do I compress multiple videos for the web using a Mac?

I'm uploading some videos to Google + and it's taking forever! So I'd like to compress the videos so they don't take so long to upload. I am aware that quicktime has a compression feature to upload ...
2
votes
2answers
1k views

Excluding Path While Compressing with TAR/GZ

I am compressing list of files like this: tar cvzf mycompress.tar.gz /dir1/dir2/file1.txt /dir1/dir2/file2.txt However when I uncompressed them the directory /dir1/dir2/ is still preserved. How to ...
1
vote
2answers
155 views

Software for lowering the colors in PNG-24 files

I am searching for a software that will allow me to reduce the number of colors for PNG-24 transparent (as in photoshop) files. Photoshop doesn't allow me any control over the amount of colors the PNG ...
4
votes
2answers
1k views

Does the RAR compression algorithm compress better than the ZIP compression algorithm?

I took 3 test files and ZIPped them. With the 3 test files again I RARred them. Each .RAR archive is smaller than the corresponding .ZIP archive. Does the RAR compression algorithm give a better ...
3
votes
1answer
8k views

How can i compress when I create SQL backup file in a folder?

I use SQL Server Express and I create backup files for all databases every day using Time Scheduling script. One script Like that; BACKUP DATABASE [Jira] TO DISK = N'C:\Backup\Jira.bak' WITH ...
0
votes
2answers
2k views

Compress big files with 7-zip, and uncompress with WIndows XP WITHOUT 7-zip

I'm using the very latest release of 7-zip to compress some files from the command line on my Windows XP machine. All the small archives work fine... but the bigger ones... always give "invalid or ...
5
votes
3answers
6k views

The compression cannot be performed because the path to the file or directory 'Application Data' is too long

In Windows 7, whenever I tried to compress the USER directory into a .zip file I experienced this error and cannot continue: The compression cannot be performed because the path to the file or ...
1
vote
2answers
791 views

Linux: Compressing files despite low disk space

I use Linux. I coded a screenshot program some time ago and now I have 9 GIG of screenshots, 60000 JPEGs, most of them look pretty similar, and I have 300 MB of disk space remaining. What are some ...
4
votes
1answer
402 views

Tar - split files

i am using the following command to backup and sql file: tar -zcvf "$BACKUP_DST/$FILE_NAME.tgz" "$BACKUP_DST/$FILE_NAME.sql" i want to make sure the compressed file wont be larger then 300mb, if it ...
24
votes
6answers
3k views

How can I evaluate the best choice of archive format for compressing files?

In general, I've observed the following: Linux-y files or tools use bzip2 or gzip for distributing archives Windows-y files or tools use ZIP for distributing archives Many people use 7-Zip for ...
74
votes
4answers
84k views

How to specify level of compression when using tar -zcvf?

I gzip directories very often at work. What I normally do is tar -zcvf file.tar.gz /path/to/directory Is there a way to specify the compression level here? I want to use the best compression ...
0
votes
2answers
1k views

Archive format & tool for large amounts of data (50gb+)

I only realised this afternoon that the ZIP format has a limit of what appears to be around 20gb. I am trying to automate an archive process (using Automate) to zip/rar/whatever a collection of ...
0
votes
0answers
4k views

What is alternative to Opera Turbo for Firefox?

I want to use something like Opera Turbo on Firefox. I want such service to be secure, so it does not collect information about me it should be encrypted Thanks:)