7z An Existing Tar File

Question

I am on ubuntu 20.04 and I have a 71GB.tar file that I would like to 7zip before moving it to long-term storage.

I can create a new directory.tar.7z using:

#tar cf - directory | 7z a -si directory.tar.7z

However, I cannot

#7z a -si directory.tar.7z

It just freezes.... no errors...

How can I 7zip pre-existing tar archives?

score 1 · Accepted Answer · answered Aug 13 '22 at 11:19

1

Tell 7z to create a new archive containing the tarball:

7z a directory.tar.7z directory.tar

answered Aug 13 '22 at 11:19

Stephen Kitt

411,918
54
1,065
1,164

score 1 · Answer 2 · answered Aug 13 '22 at 11:59

#7z a -si directory.tar.7z
It just freezes.... no errors...

It does not freeze, it waits for data on its stdin. -si means "read data from stdin" (and it made sense in case of tar … | 7z a -si …). BTW, how is the command that allegedly freezes supposed to know you want to compress 71GB.tar?

If you want to stick to -si, you can provide the file via stdin:

<71GB.tar 7z a -si directory.tar.7z

but 7z will store it inside the archive as directory.tar. You can specify a name though:

<71GB.tar 7z a -siArbitraryName directory.tar.7z

The easiest thing is not to use -si at all:

7z a directory.tar.7z 71GB.tar

7z An Existing Tar File

2 Answers2