Questions tagged [compression]
Shrinking (compressing) and restoring (decompressing) of data.
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Are .DAT files the same as compressed files in Unix?
Please confirm if .DAT extension files are the same as compressed format files (.zip ) in Unix. As I try to use gzip filename.DAT then is the original 2 GB file size the same after compression? Is ...
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Compression, and a disk image of a LUKS container
I have a dd image of disk, which is a LUKS container containing a filesystme, and which I can loop mount and unlock to access the files. The filesystem in the container is only about 1/4 full. What ...
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Common practices for backup compression levels
This question may be a bit "opinion based", but please consider it as looking for authoritative source of information on the use of compression levels.
I have a server with few databases ...
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Record count and cksum on compressed file
There is a file of 40 GB in gz format. I want to find the record count and cksum of this file in uncompressed format. One approach I have is:
Unzip the file using gunzip
Use wc, cksum commands on ...
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tar lzma autocompression produces the error "This does not look like a tar archive"
The following script
mkdir test && cd test
mkdir files
touch files/{1,2,3}
tar --create --file "test.lzma" files/{1,2,3} --auto-compress
mkdir extracted_files
tar --extract --file &...
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How can i use ffmpeg to compress a .mp4 ( h264 ) to a smaller size without quality loss? [duplicate]
Hello i am kinda new with ffmpeg and learning everyday, i am now looking for on how i can compress a video in a smaller size. since i have some 1920x1080 mp4 files with a rediculous high size.
For ...
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How do I view contents of initramfs.img in Debian-based distributions?
I often have open questions regarding the booting of a machine with GNU/Linux installed. In such cases, it could be helpful to view which files are present in the initramfs image. I have googled for a ...
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How to use jpegoptim to have files only 20kb in size?
I have tried using jpegoptim and even tried the manpage but am stumped. Here is a file I want to reduce to 50k and even open to reducing quality of the data -
Image:
Filename: shirish.jpg
Format: ...
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How to extract all uncorrupted file from bzip2 compression?
I am trying to uncompresss a bzip2 file (~55 GB) with the command
tar -jxvf file.tar.bz2
However I found that the decompression process gets stuck at a certain file and, after waiting a long duration, ...
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Compressing small files with gzip makes its size smaller than with bzip2, why? [closed]
I have a question, just a little thing couch my eyes
it's about compression with gzip and bzip2:
If I understood correctly - bzip2 requires more processing power but compresses files smaller and more ...
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Why GZIP utility cares about extension?
Whenever I need to decompress a file which was compressed with Gzip, I need to rename the file with a .gz extension , I tried other compression utility like zip, bzip2 and they don't seem to care ...
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Unable to decompress gzip file ("not in gzip format")
I've been tasked with diagnosing an issue with a webpage, and I've been able to trace the issue back to a gzip'ed JavaScript file, jquery.min.js.gz. To view the code, I've downloaded and attempted to ...
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Create a tar.gz file from a different directory, tar must keep files in specific directory structure
Here is my file structure. I am currently residing in test2/ directory, and all commands must run from there.
test/
|_test2/
publish/
|_subfolder1/
|_f1
|_f2
|_f3
|...
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Read file size from tape
I have a tape with a .tar.lzma archive written to it. How can I determine the size of the .tar.lzma archived as is? In other words, I'm looking to find the size of the compressed archive, not the size ...
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Why initrd size is not fixed?
After update-initramfs -c -k KERNELVERSION(I didn't do any change and just type this command), the initrd will always has different size with the previous initrd.
And this situation happen on Debian ...
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How do I uncompress a file with lots of zeroes as a sparse file?
I have a compressed raw image of a very large hard drive created using cat /dev/sdx | xz > image.xz. However, the free space in the drive was zeroed before this operation, and the image consists ...
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Reduce the filesize of a PDF with text?
I have a PDF created with PDF Sandwich. Each page of the PDF contains a background image and some foreground text.
I want to reduce the filesize (not the resolution) of the background image - and ...
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Archive folder onto server, compress on the host
I try to do the following:
Upload a folder (say Pictures) onto a server
Let the server compress the input stream and save it to a file
Importantly, step 1) should be uncompressed as the connection ...
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Compare zip file and extracted directory
What is the simplest way to compare a zip file and a directory that has been extracted from the zip file? I would like to delete the zip file if they are the same.
Example. Need to check if Archive....
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Exclude directory from tar
I try to compress my wordpress directory /srv/www/vhost/wp-intranet.
But I need to exclude the directory /srv/www/vhost/wp-intranet/wp-content/uploads/
First I changed directory to /srv/www/vhost/ ...
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Tool to detect and give info of compression method
What is utility tool to detect and give info of compression method (preferably more info) in any mean (CL or GUI) ?
IOW what windows 7z tool equivalent for Linux, giving info easily in GUI?
user495498
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7z command to create a XZ file
The man page says 7z tool supports 7z, LZMA2, XZ, ZIP, Zip64, CAB, RAR, ARJ, GZIP, BZIP2, TAR, CPIO, RPM, ISO, most filesystem images and DEB formats.
And it says we could pass the type as -t{Type}. ...
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How to increase the compression level of SSH tunnels
This is how I establish an SSH tunnel (dynamic port forwarding using SOCKS) from a local computer to a remote computer:
ssh -C -N -D 12345 [email protected]
I use compression (-C) because my bandwidth ...
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Mounting zip files (plural)
I know I can mount a single zip file as a directory for read-only access (Mount zip file as a read-only filesystem) but if I have a directory (or a directory tree) containing many zip files, is there ...
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can't uncompress a gzip compressed data
I have extracted a file 'linux' from ubutu installation .iso file.
The command file linux gives me this output.
linux: gzip compressed data, was
"vmlinuz-5.4.0-42-generic.efi.signed", last ...
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