I have a 44GB 7z compressed file that I compressed with lzma2 and it took around 11 hours (original file is a text file of 285GB).

7z a -t7z Files.7z -m0=lzma2 -mx=9 -aoa

So, what I want is to do is to split the file without re-compressing it, to be able to upload/download over simultaneous connections

How would I split and join such a file without going through the 7z recompress process again?

  • 1
    Please tell us what you have tried. – Rui F Ribeiro Sep 7 '18 at 11:03
  • Nothing really, i just compressed original file with lzma2 for see how much time/ how much i can compress it(from 285GB to 44GB). Im asking how i can split and once i know how its splitted, how i can get with all splited files, the original file again. – Local Host Sep 7 '18 at 11:06
  • The network speed won't increase when transferring multiple smaller files. In fact, it may be slightly slower. – Kusalananda Sep 7 '18 at 11:35
  • it is, i just test it, when i upload 5 files of 5gb i get upload speed total of 350mbps and downloading the same( i have thath contracted with my network) if i do all in 1 file i do not get more than 100mbps in downloading/uploading. And they have enough speed cause its google cloud. – Local Host Sep 7 '18 at 11:39
  • @Kusalananda Yes it does: latency has an effect and that is what download managers do. Local Host As you seem to attract downvotes, I've edited your question to become more succinct and to the point. ;-) please approve edit? – Fabby Sep 7 '18 at 12:06

From man split:

split - split a file into pieces

so the command becomes:

split --bytes=2M Files.7z

this will then create multiple files of 2Mbyte in the current directory named xaa, xab, xac, ... if you want more versatility in the name creation see man split.

To join them back together have a look here

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  • and how do i get the original file from the splitted files? – Local Host Sep 7 '18 at 11:33
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    @LocalHost . cat the files together in the right order, then uncompress the resulting file. – Kusalananda Sep 7 '18 at 11:34
  • okay, then best would be to output splitted files be a number like part1 part2 part3 etc. its possible? so when i cat i know what to put first – Local Host Sep 7 '18 at 11:35
  • Updated answer. @LocalHost – Fabby Sep 7 '18 at 11:41
  • 1
    with the split output these seems to be the way to go "cat xa{a..g}" , thanks for your help @fabby – Local Host Sep 7 '18 at 11:44

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